In my private forum within the IMD Forum (my Internet Marketing Forum,) I frequently get asked “Josh, how can I improve my Adsense CTR?”
I don’t believe I’ve ever covered this subject here on the blog, but if I have there’s nothing wrong with a refresher, so here it goes:
1. Understand that your own site impressions can greatly reduce your adsense CTR (when YOU visit your own site pages multiple times.) Any time an ad is shown, no matter who it’s shown to, it’s added to the total impressions within your adsense account and those impressions are what is used within Adsense to determine your CTR. That’s fine though. It doesn’t hurt you. You just need to know that and keep it in mind.
2. Always consider quality of traffic. If you participate in low-quality traffic building schemes like traffic exchanges etc. your CTR is going to be MUCH lower than if the majority of your traffic was coming from high-quality sources like Google. Another big one is forums. Posting your link asking for a design critique (for example) in a forum is going to increase your impressions, but few, if any, of those visitors are going to be clicking ads.
3. Ad unit positioning is very important. One large rectangle unit directly below the title is the most effective on most layouts. Use channels within your adsense account. Do some testing. The units that are producing extremely low CTR’s should be removed. Use only the ads that produce the best results. In most cases ONE ad unit will do.
4. Matching the ad to the layout is usually the best option. Many people believe an ad should stand out. In some cases this is true, but not with adsense link units. The title in your adsense ads should have the same color as the links on your page. The background should match the background color of your page and the text should match the text color on your page.
(late addition) Also, as Patrik pointed out, sites with frequent return visitors like blogs and forums will typically yield a naturally lower CTR, as frequent visitors tend to ignore ads.
These are the four biggest factors in Adsense CTR. Get them right and you will USUALLY enjoy a very high CTR.
HOWEVER, some niches just don’t produce a high CTR for whatever reason. So try to get all of the points above correct then you should see the true CTR of your niche.