How many horizontal AdSense ad-frames I can add to my webpage - one below the other, with one mm gap among them ? 3 in max or more ?
According to google TOS, 3 adsense ads in a page is max. Aside from those you can have 2 search boxes, one link ad, and 4 referral buttons in every page.
3. I think you'll find 2x 300 or 2x336 square boxes side by side offer better returns than 3 468's and look better.
I'll recommend to get minimum ads displayed on your page to get better CPC and better user experience, it will help you in long run.
I'm using a maximum number (3). But I don't have any CPC at all. Can anyone suggest me how I can improve CPC?
db4t: like Mong said, having less ad units will improve the CPC of each ad link. Google will always put the highest CPC ads in the first ad unit and so on. And you also want the *first* ad unit in your page code to also be the one that is displayed first to the visitor. This is sometimes not happening due to CSS.
I think horizontal ad units at the top of a page are wasted. Site visitors are not going to look at ads as the first thing they look at on the page. Then if you have other ad units further down the page, you've wasted the highest paying ads on the unit that gets no attention.