What does Split Testing mean?

Split testing is a basic tool of optimization on the web whose end goal is typically to get users to increase their clicks on ads in given ad space. It can be used in any online advertising context, however it has become an essential tool in managing Google AdWords campaigns. Without proper split testing, it's likely you'll piss away your money on an AdWords campaign faster than at the roulette table in Vegas.

How Does Split Testing Work?

In the design realm, split testing can have numerous variables to test such as placement, color, font, text size, styles, visual images, etc. In the realm of online advertising such as the case of Google AdSense, the variables basically boils down to which text works best.

It's really pretty simple. Other things being equal, meaning that the landing page, ad position, etc. are equal, split testing can tell you which title and ad text are more effective. Create two ads, and then analyze the click through rate (CTR) of each over a sufficiently large sample size as to be statistically meaningful. Jettison the ad with the lower CTR and create a new ad and repeat until you are satisfied that you've maximized your CTR.

That's about all there is to it (though sometimes the results are pretty surprising).