Attribution Wars: In Defense Of The Last Click (Part I)

I went to a party last week. It was put on by a big online player, mainly to thank agencies who buy large gobs of display ads for their clients. And strangely, one of the hosts began apologizing to me (over the gurgling sounds of me thanking him for the free drink—how they let me in there, I’ll never know). “As an individual, between you and me, I’d never advocate a lot of this inventory. Hey, I come from the performance side. I worked [in a senior position for a search advertising platform].” But in his current role, he was doing a pretty good job; thanking the buyers of digital display media is a fun job, made easier by their rampant demand for it.

Search ads sell themselves with performance, to those who obsess about it. Venue: spreadsheet or analytics interface. Brain usage: left brain, mostly.

In a funny way, display also sells itself, to agencies and advertisers who—for other reasons—just plain want it. Venue: the social scene. Brain usage: right brain, mostly.

Are those two worlds about to collide? Maybe they are, and it could be the death of those thank-you parties. You guessed it. The display people are now armed with spreadsheets, analytics and attribution models. And while the search nerds go rock climbing to beef up the neglected studly parts of their personas, the guitar players, prom queens, and jocks at the agencies want into the nerds’ world. Armed with slick studies and recently-purchased designer specs, they’re banging on the door of performance marketing. It’s high school in reverse!

But are there really lenses in those glasses? And are the new attribution models favored by the display people making any sense?

One of the got-good-grades analytical types, Wister Walcott of Marin Software, doesn’t think so. At SMX East recently, he threw down the gauntlet. At 6-foot-8, Wister is a nerd you don’t want to mess with.

Leaving display aside for now, and focusing just on the paid search side of the equation: a lot of people now believe in the myth that for accurate bidding, you would need to look at clicks prior to the last click. Walcott, using data from brand etailers Marin Software works with, busts that myth.

Problem: 74% of purchases can only be attributed to a single click anyway. By definition, that’s the last click. Attempt to “attribute” that purchase to prior clicks or other factors? Good luck.

Beyond that, when multiple clicks can be tracked, you don’t find confirmation of the convenient “purchase path” fairy tale that people begin with one type of search (say, a generic term) and wind up with another (say, a specific branded term). Some buy cycle behavior may resemble this stereotypical model, but on the whole, the real picture of what influences people is much more complex than that.

So the next revelation: when you bucket keyword queries down into distinct types, only 7% of sales can attribute significant influence to some kind of click other than the last click.

Ergo: unless you’ve got some awfully compelling evidence to the contrary, paid search marketers, don’t be dislodged from your current practice. Which is, as you know, relying on performance data associated with the last click prior to purchase.

To be sure, there are probably several shortcomings to this case study. It makes no attempt to latch onto users over extended periods of time, doesn’t refer to a variety of potential influences such as email, direct navigation, display ads or even organic search.

But that scenario mirrors the real-world optimization environment you work in as a paid search marketer. The choice is clear: you can react as best as you can to (admittedly imperfect) data that is pretty close to 100% certain, or you can rebalance your keyword spend portfolio based on little more than hand-wringing and hearsay evidence.

So what might be “compelling evidence” of purchase behavior being influenced by various touchpoints? Don’t expect consensus here, but do stick to your instincts.

Former Canadian Prime Minister Jean Chretien perhaps said it best: “A proof is a proof. What kind of a proof? It’s a proof. A proof is a proof. And when you have a good proof, it’s because it’s proven.”

Incoherent babble, on one hand. But it aptly captures the determination to stick to your guns, for now, when you suspect you’re in the process of being bamboozled.

And how might we gather better evidence to better confirm our suspicions one way or the other? Two ways: by trusting complicated studies that aggregate other people’s results, or by gaining better tracking capability and looking at your own analytics data.

Most advertisers employ popular analytics solutions (and paid search platforms with reporting) that lack the capacity for multiple attribution. When current analytics tools make this new functionality available to the wider marketplace, you’ll get closer to being able to verify competing claims for yourself—as long as you understand how the technology works.

For maximum accuracy and comprehensiveness of user behavior tracking, these solutions are likely going to have to come from huge companies like Google that have access to more behavior data. Since the DoubleClick acquisition, and as their content networks and exchanges gain reach, their potential to develop a tracking standard has increased even more. That said, this will run up against privacy issues, especially in international markets.

I suspect it won’t be much longer that we’ll all be fumbling along using ecommerce attribution data from Google Analytics’ quirky means of tracking behavior from multiple sources, comparing it to our stats in AdWords, and wondering if there isn’t a better way to track things, and to customize our models.

Prediction: since some competing vendors have already raced ahead in this regard, then it won’t be much longer before Google plays catchup. Remember, buyers and sellers of media have often sought a mutually-agreed standard to audit performance: that’s what the “DoubleClick era” was all about back in the day. As with analytics generally, a shakeout is inevitable here. That shakeout will accelerate when Google releases products that address the new debates about multiple attribution.

I hope I’ve piqued your interest in this debate, but it’s just getting warmed up. Next time I’ll identify and assess the four major “camps” in the attribution wars.

Opinions expressed in the article are those of the guest author and not necessarily Search Engine Land.

Related Topics: Channel: SEM | Paid Search Column


About The Author: is the founder and principal of Page Zero Media and author of Winning Results with Google AdWords.

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  • billsebald

    > Are those two worlds about to collide?

    They haven’t? I thought they did. At least they did in my bubble. Good article!

  • Michael_B

    I would say the one area in which you will find compelling evidence to prove last click attribution is sub optimal would be with branded conversions. I run one site that over 50% of branded conversions are from non branded keywords, not knowing, or appreciating this would of held this campaign back from the volumes it has been able to achieve. Websites that drive sales that have a tendency to be highly latent also seem to benefit from moving beyond last click attribution.

  • Andrew Goodman


    That’s contrary to what Wister’s data seem to show.

    They don’t call them attribution wars for nothing :)

    And I emphasize that more of us need the tools to check our own multiple attribution influences, not just someone else’s.

    By disparaging the importance of last clicks and seeking to replace them with something potentially much more tenuous, I believe we’re wading into a lot of potential error. More next time.

  • andrea-wasik

    Great writing, interesting topic, love the whole nerd vs jock thing, sounds sterotypical but in my experience it’s been true. Nerds will win this war. Data and logic will defeat flash and fancy-talk.

    Can’t wait for the next installment.

  • George Michie

    Andrew, great piece as usual.

    We’ve been saying this for a long time. Alan presented our first publicized research proving that the “buying cycle” was overblown at SES in Feb 2006.

    At SMX East in the PPC Buying Cycle panel I raised the question: even if it does happen, what exactly was accomplished by the first visit if the person didn’t buy, didn’t bookmark your site, didn’t search for you by name, but instead searched on another competitive search term? Unless someone can prove that that first visit creates a greater propensity for the person to click on your ad rather than someone else’s, I’m not sure the first visit accomplished anything.

    I do think it’s important to credit the competitive search phrase in cases when competitive search is followed by a brand search. It’s not terrifically common. The most we’ve ever seen was something like 8% of last touch brand actually being preceded by competitive search. But that can be material. We give credit preferentially to the last non-brand/competitive touch.

    Give ‘em hell, Andrew!

  • Tim Cohn

    The anti-last click camp(s) are just shills for display ad sellers.

  • mlillig

    Yahoo! has had a multi-channel attribution report, within the Yahoo! Search Marketing platform, called ‘Assists’ for about 3 years now. Beyond Conversions and CPA, of course, the Assist is probably the most popular metric for our advertisers right now. It’s helped our advertisers a lot in trying to understand how their upper funnel keywords drive conversions for the lower funnel keywords. So rather than lowering the bid for specific keywords because they thought they were poor performers (via direct response, last-click metrics), they’re are now able to measure that those keywords are valuable at driving conversions for their other keywords. It’s also helped our display advertisers in measuring how clicks on their display help to drive conversions to their other campaigns (such as search)..

    Google, I know, has also released new attribution reporting:

    Better attribution reporting is leading to more spend on both search and display and it helps to prove the value of search + display convergence.

    And it doesn’t have to stop there. Attribution tools can benefit advertisers for measuring email + display + search convergenceor shopping ad + search convergence or email + display convergence, etc.

    Attribution tools are making advertisers smarter about how they manage their online ad budgets. Sure, you can continue to measure last-click conversions, but you’ll be basing your budgeting decisions on less actionable data.

  • briancarter

    Brilliant, Andrew.

    I’ve been looking forward to better analytics to visualize the touchpoint cycle but hadn’t occurred to me- the same diversity of conversion funnels we see inside some sites will happen with multi-site funnels.

    Very good point.

    Which third party PPC co is it that allows you to use a slider to favor early vs. late click attribution? Can’t remember. Have you used it? LOL sorry for the vagueness :-)

  • DavidSH

    I think the problem is that we (as Digital Marketers) are confusing “influencing” with “conversion”.

    I noticed another writer on this site citing the 2009 Forrester/iProspect study that showed 27% of users who “responded” to a Display ad performed a Search. That is nice, but what she failed to mention was that only 14% of all searchers who first learned of the product/brand via Display actually converted via Search (or as the study puts it “eventually”), interesting but hardly compelling.

    Of course looking at multi-touch points is important but bottom line its about the sales, Search is a bonifide sales channel, users still need to be convinced that the client’s offering is what they need. This “bottom funnel” view of search is a bit myopic, especially when you throw non-brand into the mix.

    To me the more compelling question to ask is what channels influence others and what can we do as Marketers to compel people to have greater interest/desire so that they will convert higher whether within their own channel or in another. If someone needs to find more information after viewing a display/search ad (or TV for that matter) then that channel FAILED to do what it was supposed to do and it should not get all the “credit”…but it should be viewed as influential and a potential opportunity for campaign improvement.


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