Google AdSense is a popular monetization tool for many online publishers. And for good reason: it’s quick and easy to set up. If you have a website, AdSense gives you the opportunity to start earning money almost immediately.

But many publishers don’t maximize their AdSense earning potential. Here are six easy ways to make sure that you’re getting the most out of AdSense.

Use section targeting.

Your website’s pages almost certainly contain content that isn’t really useful for AdSense targeting — headers, footers, sidebars, etc. While Google’s contextual targeting technology usually does a good job at picking out the most relevant content on your pages, you can assist Google by suggesting the portions of your content that Google should pay the most attention to through the use of section targeting tags.

To emphasize content, add and before and after content that you want Google to pay the most attention to. You can also tell Google to ignore a block of content by using as a start tag.

With section targeting, you may be able to produce incremental improvements in the contextual relevancy of the ads that your users see and that can generate more clicks.

Focus on location, location, location.

If you’re not paying attention to the placement of your AdSense ads, you’re leaving money on the table. Period. In general, ads should be placed as close as possible to your main content.

While this seems like a common sense observation, one of the biggest challenges to effective ad placement is conflict with design. While a 728×90 leaderboard at the top of a page or a 300×250 rectangle ad unit on a sidebar might fit well into a design, in my experience these placements are generally better suited to display ads because they’re often not close enough to content to produce an optimal level of clicks. Google offers some useful suggestions for AdSense placements that all publishers should heed.

Pick the right unit size.

A blog I help run nearly doubled its AdSense revenue when the ad units that appear in the middle of post content were switched from the standard 468×60 banners to 300×250 rectangles. To find out which unit sizes produce the best results, there’s no substitute for a little experimentation. A/B testing is a great way to do this.

Apply the right colors.

In my experience, non-negligible increases in clicks can be realized by choosing the right colors for your AdSense units. In general, “choosing the right colors” means using the background and link colors that are used with your non-ad content. Again, A/B testing can be useful for optimization in this area.

Add a search box.

Chances are you could use search functionality on your site. If that’s the case and you don’t need a complex solution, consider using the search box functionality Google offers with AdSense. Not only is this an easy way to implement search functionality, it provides an additional means to generate AdSense revenue.

Try AdSense for feeds.

If you have an RSS feed, AdSense for feeds can be a great way to develop an additional AdSense revenue stream. In general, I’ve always found that eCPMs for AdSense for feeds is higher than the eCPMs for websites so if you have a lot of RSS subscribers, it can be especially valuable.

Photo credit: Refracted Moments™ via Flickr.