"How do I know which AdSense ad formats can bring me the best results?" This is one of the most common questions asked by AdSense publishers. Google offers a wide variety of AdSense ad formats to allow publishers the flexibility to place ads that meet the needs of their websites. No one can really predict which AdSense ad formats can make you the most profits. You need to frequently experiment with different AdSense ad formats on your site and find out what works the best for you.
However, according to my experience there are several things you can do to improve your click-through-rates (CTR) with your AdSense ads:
1) Make the color of your ads to match your web page background. Don't use frames, because frames around your AdSense ads are easily spotted as ads and ignored.
2) Incorporate the AdSense code into your pages so that the ads are naturally blended into your web pages. You don't want the ads to contrast out from the pages.
3) Make sure the density of keywords in the content of your web page that will trigger more relevant AdSense ads on the page. The more relevant the ads are, the higher CTR you will get.
4) Use Google's new 4 and 5 link ad units because they seem to have a much higher CTR than regular ad format styles.
5) Although Google doesn't allow image or graphic around the ads you can place arrows or images above or below your ads to draw attention to them. Just remember don't get those graphics too close to the ads as if they are part of the ads.
6) Limit your AdSense ads to 3 units plus one link unit and carefully place them on your page so they can blend into your site and not
distract from your content.
7) Avoid horizontal banner style ads. I recommend display ads with 300 x 250 medium rectangles because it is proved to be the most productive AdSense ad format. Smaller, longer, or wider AdSense ad formats are much easier to view as ads and be ignored by the website visitors.
No matter what Adsense ad formats you choose, constant testing to see which ad formats work and which ones don't are the key to be successful with AdSense. In addition, update contents frequently is a must for repeat visitors.
Source: http://EzineArticles.com/?expert=Kogen_Chen