Marco.org

Google:

AdSense for content automatically crawls the content of your pages and delivers ads (you can choose both text or image ads) that are relevant to your audience and your site content—ads so well-matched, in fact, that your readers will actually find them useful.

Also:

Editorial Review makes sure that all Google ads are reviewed and approved by the Google team, ensuring that inappropriate ads don’t appear on your pages.

Thanks, Google!