Ad Format:
The third way to improve ad performance is to choose another ad format. AdSense provides you with many different ad formats.
In general, wide formats seem to perform better than narrow formats. This is because people can read more words at a time without having to skip a line. I've experienced that the 336x280 large rectangle, the 250x250 square and the 160x600 wide skyscraper have done best. These are quite big ad formats, of course, so they need lots of space, but if they're placed well they usually generate more income than the smaller and narrow ad formats.
Another good format is the wide 728x90 leaderboard, which does best under the editorial content of a web page or directly under the page header, in my experience. The 468x60 banner format does not convert that well, but it can still be placed in areas where there isn't much space available, i.e. directly in the page header (next to the logo) or within articles.
I hope these tips help to get your Adsense CTR up by at least 100% if not more.
Best Google Adsense Link Colors to get higher CTR?
• Match the colors of your ads with the colour scheme of your site. Blending with your sites color profile helps to identify them not as ads, but as links similar to those of your site. The more the AdSense looks like part of your site, the higher CTR you will get. You can also match the Adsense fonts with your website font design for great results.
• Blend ads with your page - remove the borders by having a similar color as your background helps to show ads as being part of your site. Do not blend text or the ‘Ads by Gooooogle’ with your background color as it is against Google TOS (Google does not like hidden text!). However, such blending may not work for you always due to banner blindness. Neither do they see the ads, not do they click on them. So sometimes a bold contrasting ad may work better depending on your website design.
• Experiment by changing the colors, background of advertisements. You have to find out what works best for your site, not others. You can also rotate Adsense colors to reduce ad blindness.