A WebmasterWorld thread has discussion around Google AdSense publishers claiming that Internet Explorer users are more likely to click on their ads then other users. As a result, as more and more people leave Internet Explorer, earnings per user is declining.
WebmasterWorld AdSense moderator, incrediBILL, started the thread, where he said:
People using MSIE tend to have a significantly higher CTR on AdSense ads compared to visitors using any other browser.
Therefore, as MSIE usage has declined from 68% to 51% on my site over the last 3 years it would also explain a steady slippage in revenue with the shift in browser usage.
You can check to see if this holds true on your web site as well. Go to Google Analytics, click on "Vistors" then "Browser Capabilities" then "Browsers." Then click on the "AdSense Revenue" tab in the chart. Then change the drop down from "AdSense Revenue" to "AdSense CTR" and you should see which users on which browsers are more likely to click on the ads. Here is my data for my personal blog:
- Internet Explorer : 6.44%
- Chrome : 3.22%
- Safari : 2.62%
- Firefox : 2.34%
As you can see, IE users even on my personal blog are way more likely to click on the AdSense ads.
incrediBILL calls this "the single most startling trend I've ever noticed since I started using AdSense."
Forum discussion at WebmasterWorld.