One of the benefits of advertisement networks like Adsense is that their campaigns automatically generate related links based on your content, but what if you could place links to products or services based on what your reader searched to get to your site?
Well it is possible, and it has drastically enhanced the way people monetize from search engines.
A free pay per click ad network, Chitika, allows you to place ads on your site that will only show up to people who have reached your site via search engine. Moreover, the ads displayed are geared not towards your site, but the keywords the user was searching.