With contextual targeting, Google system parses and analyzes the content of a webpage, conducts an auction among the relevant ads, then serves the winning ads -- all in the blink of an eye! Now Google’s rolling out a series of enhancements to AdSense's contextual targeting capabilities to more accurately match relevant ads to webpages. The changes’ll be applied automatically. Please keep in mind that these changes won't affect how other types of ads are matched to your sites; for instance, you'll continue to see placement-targeted ads when advertisers bid to appear specifically on your pages.