Here are a few of the leanings that we found had the most impact on our revenue. This may be common knowledge among publishers, but it took us a while to come this far, and cost us tens of thousands of Euros along the way.
Unfortunately, the AdSense Terms of Service disallow disclosing of the exact CTR or other figures, therefore limiting meaningful discussion – probably that’s why we didn’t find useful articles when starting!
Split test everything. The software mantra of “Don’t touch it when it’s not broken” does not apply here. With AdSense, continuous improvement is key.
I learned that I’m utterly useless about predicting the outcome of split tests. I never guess right if some color will do better than another. I actually have to test everything. For example, on a bilingual siet that we have, a red border around the ad performed much better on the English version and much worse on the Spanish version. Impossible to guess something like this without testing.
How to split test AdSense: AdSense now has split testing built in! Before that feature, we had to come up with our own solutions. This makes life much easier.
Color optimization: Should you go for a blended palette or for ads that really stand out? Again there is lots of conventional wisdom around this area which you may completely throw out of the window once you actually start testing. We have not found a single answer to this question – except that you should test!
Placement. Probably the single most important factor of the CTR is the placement of the ads. You have to give special attention to the publisher guidelines here, for example not to place ads too nearby navigational elements. However, it can make be an easy 0.5% difference in CTR if you place an AdSense unit a little bit higher above the fold than in the center of the page. Again, they key here is testing variations.
Best performing ad units first. Google displays the highest paying ads in the first ad unit of the page. So make sure that first unit is your best performing one! You may need to use CSS positioning to show ad units higher up than they are actually in code. For example, you may have a header ad that doesn’t perform well and a in-content ad that performs well; you would now use CSS to position the header ad unit in the header of the page even if in the source code this ad unit comes second.
Section targeting: Using section targeting, you can highlight to the AdSense bot which parts of your page contain the main text body to which the ads should be targeted to. This can make a huge difference by serving ads that are actually contextual.
Direct placements: AdSense has two ways of serving text ads: In the first way, Google does all the logic of trying to understand your page and the visitor to serve contextual ads. The second way lets advertisers target your site directly and place ads in specific channels on your site (if they are enabled for it). It’s important to know about this, since the CPM and CTR can be wildly different for the two scenarios. If you go to a channel in AdSense that is currently enabled for external placement, there is a link called “View 7-day earnings” which shows a report comparing the direct placement performance versus Google’s. In our case, the direct placement was generally under-performing by 30-40% except on specific pages, so we disabled direct placement for many channels.
Heat maps: While basic heat map optimization is explained by Google, it took us awhile to apply it across different sites. Here is just an example of how a “minor” repositioning can add over one percent to your CTR.
Just moving the information sidebar (company logo and some text) on our South America business directory from the left of the content to the right increased the CTR by more than one percent.
Demographic-based optimization: Since most of our sites have anonymous traffic, we rarely do this, but for web properties with many signed in/identified users, this is huge. I’ve seen examples where just serving different colors for men and women lead to a CTR doubling. I’m sure this is taken to excellence by the big portals.
Hire an AdSense optimizer: If an expert is able to increase revenue by 20% on an account, then for sites that have at least some basic AdSense revenue (5k/month plus) this would be a worthwhile hire.
Meanwhile, just keep optimizing, it’s actually one of the fun parts of the online business because every bit directly translates to more money in your or your company’s pockets.