Tip Number 1.

The lesser the ads you place, the higher the likely hood of them getting clicked. As a rule of thumb, I always never put more then 4 ads on any single page although I would be hard pressed to think of times when there were more then 2. More ads would mean a decrease in the value of the advertisements shown, so publishers should carefully watch their advertisement units, as it dilutes ad inventory and value.

Tip Number 2.

Give them a reason to click. No not by asking them to