15 Reasons why all Unique Visitors are not created equal…

Analytics · By On · 4 Comments

Since my last post­ing about unique vis­i­tors and vis­its, I’ve received a great deal of feed­back. Much of this feed­back praised my blog, with one reader say­ing it was “a voice of rea­son” in an oth­er­wise “ill informed web ana­lyt­ics indus­try”. That may be a bit strong, but I love it nonetheless!

As might be expected, my post was also met with some push­back — which is also great. I’d hate to post some­thing every­one agreed with…what’s the point of that? Now these folks had some ques­tions and indeed some mis­un­der­stand­ings that I wanted to clear up.

So the theme of this post­ing is sim­ply that all unique vis­i­tors are not cre­ated equal.

To some of you, this may be com­mon sense. To oth­ers, this is new infor­ma­tion. And to oth­ers, this is purely hereti­cal. “How dare you ques­tion my unique vis­i­tors?! Such blasphemy!”

I know, I know…I’m always rock­ing the boat. But the web ana­lyt­ics indus­try is so young and clouded by mis­per­cep­tions that some­one needs to step in and put a stake in the ground. And why not me? So here it goes…


STARTING WITH THE BASICS
Rather than hav­ing an emo­tional debate about the accu­racy of unique vis­i­tors and whether you should or shouldn’t use them, let’s start with some basic observations:

  • Fact #1: Most web ana­lyt­ics sys­tems rely upon cook­ies to iden­tify unique visitors.
  • Fact #2: Cook­ies are set at the browser-level by domains like omni​ture​.com.
  • Fact #3: If cook­ies are not accepted or used by a domain, web ana­lyt­ics sys­tems mostly rely on IP+user agent com­bi­na­tions and/or uni­ver­sal vis­i­tor iden­ti­fiers (i.e. a reg­is­tered user ID)

15 REASONS WHY ALL UNIQUE VISITORS ARE NOT CREATED EQUAL
Now assum­ing you agree with those obser­va­tions, let’s look at 15 sce­nar­ios that impact the accu­racy of your unique vis­i­tors counts:

  • Sce­nario 1: One per­son uses mul­ti­ple browsers from one com­puter from one location
  • Sce­nario 2: One per­son uses mul­ti­ple browsers from mul­ti­ple com­put­ers at mul­ti­ple locations
  • Sce­nario 3: Sev­eral peo­ple use one com­puter with one browser from one loca­tion (i.e. a typ­i­cal 4 per­son household)
  • Sce­nario 4: Sev­eral peo­ple use one com­puter with sev­eral browsers from one loca­tion (i.e. a typ­i­cal 4 per­son household)
  • Sce­nario 5: Sev­eral peo­ple use sev­eral com­put­ers with sev­eral browsers from one loca­tion (i.e. an increas­ing trend among households)
  • Sce­nario 6: One per­son deletes cook­ies for one browser
  • Sce­nario 7: One per­son deletes cook­ies for mul­ti­ple browsers
  • Sce­nario 8: Your web ana­lyt­ics pack­age reports both cook­ied and non-cookied users in the unique vis­i­tor counts
  • Sce­nario 9: Your web ana­lyt­ics pack­age doesn’t use cook­ies or reg­is­tered IDs to iden­tify unique visitors
  • Sce­nario 10: One per­son rejects cook­ies on one browser
  • Sce­nario 11: One per­son rejects cook­ies on one browser, but accept cook­ies on another (for exam­ple, Inter­net Explorer vs. Firefox)
  • Sce­nario 12: Many peo­ple from one com­puter reject cookies
  • Sce­nario 13: One per­son rejects cook­ies from one com­puter but accepts cook­ies on another computer
  • Sce­nario 14: IP pool­ing by major ISPs like AOL means many IP addresses for one vis­i­tor as they move from page to page on your website
  • Sce­nario 15: Ded­i­cated Cor­po­rate IP addresses and stan­dard­ized browser con­fig­u­ra­tions mean one IP address for many people

SO WHAT IS YOUR UNIQUE VISITOR COUNT?
At any given point in time, all of these sce­nar­ios are play­ing out on your web­site and are inher­ent in your unique vis­i­tor counts. Whether you like it or not. And just for the record — these are not ven­dor spe­cific issues as one of my read­ers sug­gested. Hope­fully you can see that every sce­nario I’ve listed above has lit­tle to do with your web ana­lyt­ics plat­form. Rather, they are byprod­ucts of web mea­sure­ment in general.

So what is your def­i­n­i­tion of a unique vis­i­tor? How many “uniques” do you really have? More impor­tantly, how many “peo­ple” or prospec­tive cus­tomers are you really reaching?

If you get 1 mil­lion unique vis­i­tors in a given month, is that 1 mil­lion oppor­tu­ni­ties to sell? Or is it just 500,000? Maybe Sce­nario 3–5 are really heavy in your site traf­fic mix, and you have 1.5 mil­lion unique “prospects” that you could convert.

No mat­ter what the case, given all 10 sce­nar­ios above, what num­ber would you feel con­fi­dent report­ing back to your CEO? Can you have con­fi­dence in a unique visitor-based con­ver­sion rate? Or even a unique vis­i­tor count? Some of the sce­nar­ios I’ve listed above will inflate your unique vis­i­tor counts and some of the sce­nar­ios will decrease it. Some will actu­ally do both! And it’s nearly impos­si­ble to mea­sure the net impact of all these factors.

USE VISITS…AVOID UNIQUE VISITORS
For these rea­sons, as I sug­gested in my first post on Vis­its and Unique Vis­i­tors, I almost always use Vis­its as a strate­gic mea­sure of how well my sites are con­vert­ing prospects. If noth­ing else, each Visit rep­re­sents an oppor­tu­nity to con­vert a prospec­tive cus­tomer. It’s no more com­pli­cated than that. And because vis­its (or ses­sions) are gen­er­ally mea­sured based on cookied-visitors only, they are much more accu­rate than unique vis­i­tors (vis­its are in effect a sub­set of unique visitors).

Vis­its, by def­i­n­i­tion, also do not require you to deter­mine “unique­ness”. In other words, all Vis­its are cre­ated equal.

Of course, rely­ing on vis­its has draw­backs in mar­ket­ing analy­sis, seg­men­ta­tion, latent con­ver­sion, life­time value, etc, etc. But that’s OK because by the time you get to these draw­backs, you shouldn’t be focus­ing on unique vis­i­tors any­way — you should be focus­ing on unique cus­tomers.

So what is a unique cus­tomer? Why is it bet­ter than unique vis­i­tors? And why won’t it suf­fer from the same inac­cu­racy issues? As much as I’d love to dive into that now, you’ll have to stay tuned until my next post — I’m all out of time today. In the mean­time I wel­come your feed­back and as always, if you’d like assis­tance under­stand­ing how to lever­age web ana­lyt­ics to max­i­mize ROI, please do not hes­i­tate to con­tact me and the Omni­ture Best Prac­tices Group.

Tagged with:  
  • Jon

    Hi Matt.

    Do you know of any com­pa­nies who require reg­is­tra­tion that have com­pared their Omni­ture uniques against their more accu­rate reg­is­tra­tion logs to mea­sure how off the for­mer num­bers might be?

    Thanks

  • http://blogs.omniture.com/author/mbelkin mbelkin

    I do actu­ally, although as you might imag­ine I can’t men­tion their names. I also did a sim­i­lar analy­sis myself when I was a cus­tomer of ana­lyt­ics many years ago. This was well before the unique visitor/cookie debate, I was actu­ally more inter­ested in under­stand­ing multi-channel behav­ior. In either case, my expo­sure to these ini­tia­tives has con­firmed one thing – vari­ances in the accu­racy of unique will dif­fer by web­site. There really isn’t a hard and fast num­ber you can use to esti­mate it. Quite frankly I’ve seen num­bers in the low sin­gle dig­its, all the way up to high double-digits. All of these are based on a registration-based analy­sis of uniques. If you don’t require reg­is­tra­tion on your site, look to some of your peers in Media or eCom­merce, as reg­is­tra­tion is quite per­va­sive there.

  • Pingback: Lies, damn lies, hits and views at First Drafts - The Prospect magazine blog

  • Pingback: O RLY? AOL’s Reports +11% Unique Visitors, +35% Page Views (3/07 — 3/08)