Multiple ad units can help optimize your performance by leveraging our large inventory of ads. You can put up to three standard AdSense for content ad units (this includes a maximum of one 300x600 ad unit), three link units and two AdSense for search boxes on each page of your site. Remember that the best way to measure the effect of multiple ad units is to examine the impact on your overall earnings. Multiple ad units may prove particularly successful for the following pages:
- Pages with lots of text, requiring users to scroll down the page.
- Forum or message board pages, particularly within threads.
- Pages where only smaller ad formats (such as the 125 x125 button) will fit.
Tip for maximizing multiple ad units: make sure that the ad unit with the best location on the page is the ad unit that appears first in your HTML code. This will help ensure that your prime ad real estate is occupied by the ads that place highest in the auction and will generate the most revenue for you. Find out how to define the first ad unit.