I’m at The System seminar and I just heard Trevo Claiborne from the Google Website Optimizer team speak. He casually mentioned they recommend ONE HUNDRED conversions/action PER OPTION you are testing.
This is in direct contrast to the standard rules of thumb circling around the direct marketing world. (Most say 30, or 40 maximum is plenty).
Now, with my statistical background, rules of thumb have always bothered me in the first place. I’d rather see the appropriate statistical test applied, but I DO understand the practical need to move at the speed of business and use heurisitics and shortcuts.
But I was incredibly surprised to hear Trevor say ONE HUNDRED in contrast to the 30 we’re all used to hearing. So I asked whether this was based upon their observations across all their advertisers … I got a bit of a disclaimer, and then an answer I took for yes.
Here’s why I think this is a radical statement and the implications for us all.
First of all, Google knows.
I’m not doubting their observations.
They must SEE something we don’t. And I’m guessing what that is … what it MUST be, is that there is MUCH MORE NOISE on the internet than there is in traditional direct marketing environments.
This explains why so many clients report confusion after having declared a winner … then later find their profits haven’t really risen correspondingly.
So we probably should all lean in the direction of longer lasting, more statistically robust tests … which translates to MORE actions before making a decision.
On the other hand, the vast majority of clients I’ve spoken with don’t have the necessary traffic to accomplish this in any reasonable time frame.
So what’s the solution?
FEWER AND MORE WELL CHOSEN TESTING OPTIONS RUN LONGER. It really doesn’t make sense to throw everything against the wall. Do your research first and foremost to determine what MIGHT be likely to improve your conversions. This means surveying people as they’re exiting your page, installing live chats, monitoring competitive sites, reading repeatedly appearing sales copy in your market and identifying very strong candidates for conversion enhancement.
A plain old A-B test with well thought out inputs is probably more valuable than testing umpteen different options.
Of course, Taguchi starts to look more attractive in this situation (a method of compressing dozens of tests into one), but you have to remember that the same rules apply … we need MORE actions than we’re used to considering before we get really robust and stable results.
Which means your inputs for Taguchi testing are even more important.
Google says there’s LOTS AND LOTS of noise online, and you have to test carefully and watch the results for a long time to be sure of them.
Believe them, and design your tests wisely since they’re not as “disposible” as you might have previously thought.