The previous recipe is a very good solution to try and avoid Google "Smart Pricing" by hiding Adsense to regular visitors and displaying it to search engine visitors only. Although this hack is good for achieving this goal, it is possible to have even more control over your ads and who sees these ads.
In this recipe, I'll show you a very interesting plugin for anyone who'd like to make money by blogging. It is called Who Sees Ads.
The principle of the Who Sees Ads plugin is exactly the same as the previous recipe. It allows you to make blogging money by displaying ads, but you can control who should see ads, and who shouldn't.
Unlike the hack, the Who Sees Ads plugin allows many different rules that define who can see ads and who cannot. For example, you can define that you should display ads only on posts older than 10 days, or only if the reader comes from a search engine.
