Here are some tips to increase your Google Adsense CTR:
1. Make sure the ads that are appearing on your site are closely related with your content. This is the first thing you have to do because if your ads are not relevant, there's small possibility that people will click on them. Then, what should you do to tackle this problem? Here are the tips:
* Create a keyword rich content. I suggest you creating one topic a page.
* Check your keyword rich content and then mark some of your keywords as bold or italic. But don't do it too much, just do it 1 – 2 times per page. Otherwise, Google assumes you are doing spamming.
* Use your keyword in your page title.
* Use HTML Tag H1 as your content title, and put your keyword in it. Don't forget to place this tag at the beginning of your content.
* If all those tips still do not work, there is just one possibility: there are no ads that matched with your keyword! You can check this out by using this marvelous tool from the Digital Point Website. It is called the Google Adsense Sandbox, and located in http://www.digitalpoint.com/tools/Adsense-sandbox/
You'll be asked to enter your selected keyword and it will display every Adsense ads that's connected with that keyword. What if your suspicion is correct? Change your keyword! Do not worry; sometimes you just have to change one or two words.
2. Use wide ads (336x280, 300x250 or 250x250). Because these are the best performing ads.
3. Blend your ads with your website themes. For example, if your background color is white, change your ads border and background color to white as well. If your background color is dark (black), use bright color such as yellow as link color. This will decrease user ad-blindness.
4. Place your Google Adsense in these positions:
* Above the fold
Above the fold is the top position of your page that's visible without your visitor having to scroll down. This is the best location that works for me. I place 336x280 ad unit in this location and it works very well. Why? Okay, back to our example. Your article is about "how to bake delicious bread". Someone finds it from search engine; when he opens it, he first sees ads about "baking school", "baking book" or "bread recipes". Who won't be interested?
* In the middle of an article.
This works well if your article is long (more than 500 words). People tend to stop for a while and look for something different while they read. I suggest using rectangular ads (125x125, 180x150, 300x250, 336x280, 250x250 ad unit) for this purpose and make it left justified.
* At the end of an article.
Many people reported that placing Google Adsense ads at the end of their article tends to work very well. This is because when people finish reading an interesting article, they usually think "okay, what's next?" That's your chance! By placing Google Adsense ads at the end of this article, people will spend a minute to read it and then (maybe) click it. For example, you write an article about "how to bake delicious bread". And at the end of it, there are some ads about "bread recipes". Who won't be interested?
5. Regarding the fourth tip, I don't recommend you placing three ad units in a single page. From my experience, the number of ad unit you place in a single page doesn't affect your CTR. In fact, I even found that placing three text ads in a single page make my ads "unblended". For example, I put 160x600, 468x60 and 336x280 ads on a single page. You know what? My 468x60 ads only showed 3 ads in it, whereas my 336x280 ads only showed 2 ads in it! My suggestion is: use 1 – 2 ad unit and a single link unit on your page (Google allows 3 ad unit and 1 link unit to be placed on a single page).
6. Always use Link Unit! Many people never realize that Link Unit is the most profitable format if put in the right place. Try to place it near your navigation menu. People will misidentify it as a navigation menu and automatically read it. If your ads are closely relevant to your content, there's big possibility they will click it. I move the top navigation in one of my websites to the bottom section and replace it with 728x15 Link Unit Ads. You know what? My Google Adsense CTR increased by 200%!