My first article on Search History usage was experiential; you can do the searches yourself and see the strange results. This article offers a different type of explanation with a lot more detailed argument. It raises the question for me - is Google’s use of AdWords Search History to generate adverts for unrequested keywords, fraudulent? The development of the argument travels through marketing, micro-economics and a bit of stats. I’ve tried to set a background that makes this easier to follow - but it is a bit lengthy. Sorry ’bout that.
Signs And Portents
I treat AdWords a bit like cryptography, or black box control engineering. Messages go in (adverts, keywords, bids, geotargets, etc) and translated messages come out (impressions, clicks, conversions, paid prices, etc). Google does something in the middle. It’s part of my job to infer what Google does, and manipulate inputs to optimise the output. There’s a bunch of fancy techniques that could be used (Stochastic Perturbation with Simultaneous Annealing, for example - what a wonderful name, eh?), but much of it comes down to, in my opinion, marketing messages, the buying process and micro-economics. The complex maths get their day only with large data sets and high volumes.
For small advertisers, the volume of data needed to make techniques like SPSA and Taguchi work, are hard to achieve and pay for, and subject to a lot of statistical noise caused by uncontrolled and/or unmeasured factors such as seasonality, market price fluctuations, confidence, organic search results, press releases, Google’s changing policies and procedures, the Editorial Review process, trademarking protection, and so on. Mostly I rely on techniques that appear to work in general cases, with tuning when enough historical records are established.
I determinedly read messages, signs, sigils and portents from Google - blogs, Wall Street Analysts reports, Nielsen, the occasional goat sacrificed at midnight, etc. But the most important pieces of evidence come from the AdWords account, from web analytics or web server log files, web site contents and visitor trajectory, and from looking at competitive advertising.
The consequence of a lot of thinking, experiments, and the experience derived from spending a few million of my clients’ funds in advertising budgets, is that I’ve developed some techniques that give me the most data for interpretation. I’m quite happy to share these techniques - my primary value to my clients is “insight”. Paid search work is just one tool in that shed.
I’ve found that it is most useful to focus on Exact and Phrase matched AdGroups. There’s a specific way to set these up to get the greatest signal - I’ll detail it some other time. But the effect is that even if the bid for exact matched keywords drops, that the phrase match and broad match adverts don’t run - think “negative exact keywords” and “negative phrase keywords”. Also think “This’ll Stop Google From Abusing Expanded Broad Match And Destroying My ROI”.
This technique reveals some intriguing things about users and search. Most importantly, it used to show how and when users repeated searches.
Characteristics Of Search
If you have a rare search query, as an exact matched keyword, it might only attract a few hundred impressions per year. As Google have become more experienced, they’ve started aggregating small volume queries, so this signal is harder to see now, than it was in 2003-2007. However, old records show something interesting. If you have one of these “long tail” queries, then you see that they tend to get used in bursts. You get no activity in months, and then you get a run of 2-15 (usually around three to six) searches with the same query. Then it goes quiet again, perhaps for months.
Why? Because one searcher has decided to find something and is repeating their search. I know that I do this. I’ve seen other people do it. You are trying to research around a problem and you keep coming back with the same query, perhaps to look at more results on the page, or to get a second or third page.
Patterns of search query repetition appear to vary in some ways that are amenable to analysis. AFAICS, it changes with how the search is regarded by the user (what I call the “intent”), and the phase of the buying process. If the searcher is in the early phases, then they do a lot more repeat searches. If they are late phase, for example after making up their minds to buy from a vendor - then the number of repeated searches tends to be small - they know what they want and they just have to find it. A characteristic migration of phrases might be to start with “Cheap Holiday” multiple times, then some specific searches for types or locations of holiday which may have some repetitive components, and ending up with a single search query for “Expedia.com”, “travelocity” or some other site that was identified as having the product to buy.
This evolution of search queries interacts with the new search history permutation mechanism in a regrettable way.
When a user repeats the searches, the results stabilise, and are just like the results you’d normally get from AdWords. If there’s been a break in activity, then a new search after the break duration is treated as if there is no search history. For example, type “Brazilian Tax Credit” tonight as the last search you do, then come back after a nights’ sleep and search for “US Vacation” and you *won’t* see the Brazilian Holiday and US Tax adverts (from the example in the previous article). Well, I don’t, anyway.
Prospective buyers, early in the buying process, appear to repeat searches. If these users walk up to a cold machine, boot and start searching, they see nothing different caused by the search history. However, early phase searchers are not, usually, close to buying - by definition. You can, of course, help accelerate them to purchase with the right advert copy and the right content on your site. But the general behaviour *appears* to be that multiple repeat searches are mostly coming from people who are unlikely to buy now, today.
Early phase searchers may not even be looking at paid search adverts seriously - I believe that I tend to see lower CTR’s for keywords where I regard the intent as being weak; early phase searchers often seem to use organic results rather than paid search, because organic results will often lead to pages with discussion of alternatives, while paid search typically leads to a specific solution. In other words: consistently targeted adverts are shown to the group who probably could benefit from some message variation (use those alternate creatives, marketeers!). These early phase searchers are also, typically, the lowest converting group - because they may get distracted by a different type of solution or decide to not continue with the purchase process, or the latency exceeds the 30 day AdWords Conversion Tracking or the default Google Analytics 6 month tracking or ritual cookie deletion.
In the later phases, I believe that people vary the search more. This is where they are comparing features, benefits, finding discussions and threads to justify their decision. These later phase prospects are the ones that see randomised adverts, because the search history is invoking bizarre extraneous keywords to the party.
The consequence of the evolution of search queries is that the most bizarre conjunctions of irrelevant adverts are shown to the users with the highest interest in buying right now.
This is not desirable for advertisers. This is not helpful for search users. Why do it?
Permutation
The nature of the Search History interaction appears to be a simple combinatorial permutation. That is, given “cheap holiday” and “us vacation”, it probably generates “cheap vacation”, “cheap us”, “us holiday” and “holiday vacation”. While this example generates some plausibly interesting candidate keywords for searchers, it is demonstrably weakening the answers to the most recent request. See the two examples in the previous article for details.
The core question is whether permutations of the current and previous search query generate plausible searches that the user might have made. If this was a valid technique, might we not expect it to have been used for organic search, first?
That is to say, if Google, who are probably about the largest, most rational and experimentationist entrepreneurial organisation on the planet have *NOT* used permutation to improve organic search results, why would anyone imagine that it benefits paid search to do so? I’m not aware of any previous activity in paid search that has resulted in organic search following the behaviour. I can see that Google copies lessons learned from organic search into paid search. You want some examples?
- 404 checking - 404’s are lethal for organic search, so Google verifies that paid search pages are present.
- Landing Page Quality Scores - appear to be based on what makes a good result for organic search (though I have a nasty suspicion that the nature of search evolution and the buying process implies that there *should* be a difference between organic and paid search optimal landing pages).
This paid search usage of the search history appears to be novel, and appears to offer a reduction in the overall effectiveness of searches. Combinatorial explosion also means that with lengthier queries, the number of combinations is increased markedly. Some of these may well overlap with keywords that have a higher bid and/or a better CTR - so these will be favoured over other adverts that are more directly relevant to the searchers intent.
Markets and Market Prices
OK, now we’re in the dismal world of Economics.
If I’m an advert trader, I can set up multiple markets for bidding for placement. I might set up one market for “ford prefect” and another market for “edsel”. This is like Google - there used to be a market for each keyword. Google’s Broad Match extended the search queries that were involved in the market, but usually in identifiably sane ways. So a market for the keyword “cheap holiday” could include search queries for related concepts such as “cheap vacation”, “free holiday”, places known for or associated with inexpensive vacations such as “cancun vacation” or “holiday cyprus”, and even specific company names closely associated with cheap holidays.
The more of these other search queries that I can recruit to my market, the more price competition I can engender. This is why, I think, Google likes paid search users to use Broad Match by default - you participate in a larger market and that makes obtaining a higher value price in the auction. More bidders implies a higher price from the market - I can’t currently think of a counterexample in which more participants recruited to an auction will reduce the price struck. The generalised second auction apparently used by Google, doesn’t seem to offer a way to allow larger volumes of bidders to reduce the price that is struck, compared to an auction with fewer participants.
Indeed, this observation is the entire basis of an industry - keyword finders for SEO and paid search. Find the rare keywords in which the auction includes fewest bidders, and, the argument for this industry goes, you have found the auction in which you can pay the least to obtain traffic (or use SEO to get that “free traffic”). Of course, Broad Match negates this industry for paid search to a great extent. I have (seriously) considered setting up AdWords for well established brands, in which I simply used the brand name, with carefully selected negative keywords, to do all the work. Google will gleefully match well established brands with the primary and even secondary characteristics for their main search queries. Why do work you don’t need to, eh?
So, given Google’s ability to extend an inference for, for example, the keyword “thomas” to imply “cheap holiday”, or the search query “thompson cooke” to bring visitors to a major travel site (check your web server log files and observe the mismatch between keyword and search queries - that’s where the evidence is), why would Google need to use permutation to increase the auction?
As another example, look at what happens in organic search. You miskey “erlers danlos syndrome” and it offers to correct the spelling - because the history of interactions and the nature of searches have taught Google what the normalised spelling should be. Users have become used to the idea that Google will correctly guess the question that was intended. Why would paid search uniquely require a type of search query expansion that is *not* used for organic search conceptual extensions?
I believe that Google uses search history permutation to create an artificial market. As well as related search queries, the search history drags in unrelated queries. So a chain of “Brazilian Tax Credit” and “US Vacation” searches yields combinations including “us credit”, “brazilian vacation” and so on - and you can see adverts in the primary article with these exact adverts shown. *BUT* it is a false market. These advertisers had no strong intention to appear on those searches. If they did, they’d have used those keywords - just as an organic search would have extended the searches to include those results. If Google had seen a relationship, then Broad Match should bring in those queries to the advertiser.
Is this fraud? I’m no legal expert - I have no real idea if this is technically a fraud. But doing things to paid search that you wouldn’t do for organic search at least raises the question of whether this is deceptive advertising for Google - if advertisers were operating in the reasonable expectation that search for keywords worked like search for search queries, then might Google have implicitly broken the contractual expectation for advertisers? If you create a market that recruits bidders who don’t really want to participate, so you can increase the paid price in the auction, is that fraudulent?
Local Optimisation vs Global Optimisation
I suspect that the essence of the problem is an attempt to locally optimise. For example, if you are a programmer, you can expend effort to refactor an algorithm for a local optimum, and later discover that the global performance has been damaged.
I suspect that this is what Google have done. They’ve apparently decided to stop showing adverts on searches where few people clicked on adverts. They’ve compensated for this by using a piece of information that they hold - your last search - and created a higher value market for the adverts. This increases revenue in that transaction. But I think that this creates a problem for global optimisation, and Google’s brand value - it also does very little for advertisers. Users seeing irrelevant adverts will also often blame the advertiser for stupidity, as much as they blame Google for poor quality matching.
Optimising my clients’ accounts won’t help much, though. The problem is that I can’t optimise my clients. Google has created a strange new market, apparently to boost the Average CPC at the point at which people are most likely to have abruptly shifted search focus, and are generating the most random results at the point when someone is about to buy. I can’t control Google’s recruitment of irrelevant advertisers. Even if my adverts are exactly on focus for the intent, when pushed down the list of results, I get fewer impressions and a lower CTR - because people don’t want to go wading through random garbage results. I might even get pushed off the first page. It’s simply frustrating, because it is beyond my control.
The adverts that I most need to place, are the ones that Google has apparently decided are a reasonable place to extract additional revenue from advertisers.
Monetisation
Historically, Google has succeeded by consistently producing good search results. They resisted introducing paid search until they had a model that worked - no inline search results, and an apparently rigid wall between paid and organic search results. I am in awe at the subtlety that AdWords used to have. It was a fantastic tool that I used for market research, as well as lead generation or sales.
The virtuous cycle for Google has been that good search results meant more user recommendation and so a growth of the user base. Advertisers like being able to reach a large audience.
Note how this depends on the quality of the search results page.
Evans and Wurster’s 1999 book, “Blown To Bits” (Harvard Business Press - no commission on this link, folks) was the first book that clearly explained, to me, the theoretical underpinnings of the value of Yahoo, and tied it to marketing principles that made sense for me. This book is also a great guide to monetisation and market share. In other words, it explains the economics and marketing principles behind what seems to have been a core Google strategy for the last decade:
By delivering the best page of search results, Google stays ahead of the competition, and thereby dominates search.
As we’ve seen, permutation damages the likelihood, for later phases of the buying process, that Google will give the *best* page of search results. It may be a better page than competitors, but it is not the absolute best page that Google could deliver. Arguably, when looking for a commercial solution, paid search is a better answer than organic. It depends on the market, and the state of organic results. I know that I have, and have had, over the years, clients with huge CTR’s and high conversion rates, because the organic results are wrong for final phase product oriented searches.
Does this damage the Google brand in the eyes of the search user? I think it does, and I have some clues that point to this.
Paid search vendors are intermittently criticised by industry watchdogs for failing to adequately clarify that paid search results are not chosen on the same basis as organic search results. In conversation with users, they will often hold that the number one advert shown by Google has been selected with the same or similar criterion as the number one organic search results. There is certainly a higher intrinsic CTR for the number one advert position, especially if it appears above the organic search results.
It is intriguing, isn’t it, that industry commentators and so many paid search booklets of “affiliate secrets”, emphasise that appearing as the Number One paid search result may actually dampen overall ROI. I believe that this is because it recruits searchers who are in the wrong phases. Instead of being at the point to consider purchase, these searchers are still discovering what it is they need to know, before they go shopping. They also trust Google to deliver relevant results.
What will happen to users as they approach the final phases of an attempted purchase? They will see a largely static list of advertisers for each repeated query turn into a set of adverts in which perhaps half or more of the adverts have no direct relationship to the search intent. I believe from purely personal observation and extensions of marketing psychology, that users will extend less trust to paid search results, especially when the top poistion from advertising is clearly off-topic - as it is, accidentally, in both of the test cases that I previously published.
Far from demonstrating Google’s long term commitment to improving search results, permutating the recent search history appears to weaken page relevance, and this drives down the long term monetisation of search - because it means that other vendors offer a relatively better search results page. This is really good news for Yahoo! and MSN. Their adverts will actually have a higher trust placed on them, so long as the auction is kept reasonably fair and uses only the contextual extensions that organic search would use to extend the keyword to similar *weighted* searches. If I was a user, looking for things to buy, and in final phase search, I’d change my strategy to use MSN or Yahoo! - because I’d get more consistently focused adverts, that help me achieve my ends.
Advertiser Effects
Because Search History Permutation enlists more advertisers, the effect is quite interesting. Painful. But definitely interesting. It seems to differ according to your normal bidding strategy.
If you typically bid below position 5, then you are likely to be pushed further down the page, or even off the first page. Impression rates will decline, sometime markedly. CTR will be typically somewhat decreased - but no huge decrease in CTR, I think. You should see that your average position is declining, as irrelevant adverts are brought in above you.
If you typically bid above position 5, you may be recruited to show adverts on irrelevant searches - your adverts have a high CPM, making them valuable for Google to show elsewhere. The result is booming impression volumes, as your adverts are shown on searches you don’t care about - and your CTR crashes down. I think that your average position will be largely unaffected.
Any way you slice and dice it, this looks like a poor move for advertisers.
Summary
Searchers evolve their search queries during the buying process. From my research, the greatest variation in search queries appears to happen as searchers near the actual purchase. The final search appears to consist of a single query - for the business that was identified as the right one to buy from. This is statistical inference - so for some users there will be a single search, and for other users there many be multiple repeat searches that lead to a sale; the argument is not invalidated by a single counterexample - you need a chunk of data to reveal that this is wrong.
Google’s current use of search history recruits new keywords to participate in the auction, resulting in the appearance of adverts for which the searcher has demonstrated no interest.
This appears to be something that is not in the best interests of searchers.
This appears to be something that is not in the best interests of advertisers.
This appears to be something that is intended to increase revenues to Google, by manipulating the conditions in which bids are evaluated.
The exposure to additional participants in the auction appears to allow a higher price to be returned from the auction.
This appears to damage the long term brand value of Google, at least for advertisers and probably for searchers.
It appears to offer comfort to Yahoo and MSN search - their page values are now relatively higher than they were before Google made this change.
If this isn’t evil, what is it?
If this isn’t fraudulent activity, what is it?
This appears to be yet another example of covert messages from Google that indicate how they really think. Ignore the babble about how much they love you. Google apparently thinks of advertisers as gullible stooges who are there for the money they yield. Advertisers, for Google, it seems, are a resource that demands no respect. They won’t tell you this, but it is how they treat you - sending you clicks that won’t convert is great for Google and lethal for your business. Removing Advertisers ability to control click quality is great for Google and destructive for the relationship between Google and Advertiser.
Trust is earned, but it is fragile. Google keep destroying the trust that their organic search results have built, when dealing with advertisers.
Update
2008-03-18 Slightly clarified criticism of Google, bringing it back to AdWords, in the summary. I vacillate as to how much damage this does to the relationship between Google and Searcher, and between Advertiser and Searcher. Seeing irrelevant AdWords adverts is often, but not always, blamed on stupid advertisers.
