You can set your preferences for how Google advertises to you using the Google Ad Preferences page, and if you want to you can opt out of interest-based advertising entirely by cookie settings.
Cookie: DefinitionA small file saved on people's computers to help store preferences and other information that's used on webpages that they visit.
Cookies can save people's settings on certain websites and can sometimes be used to track how visitors get to and interact with websites.
Sometimes cookies can cause problems when you're signing in or moving through your AdWords account. When this happens, the best way to fix this is to clear the cache and cookies that are saved for your Internet browser.
Clear cache and cookiesCookies, which are files created by websites you’ve visited, and your browser’s cache, which helps pages load faster, make it easier for you to browse the web.
Clearing your browser’s cache and cookies means that website settings (like usernames and passwords) will be deleted and some sites might appear to be a little slower because all of the images have to be loaded again.