This is a very tricky area and you more than likely won't be approved for a Google Adsense account on a file sharing site like FileHippo. On a free file sharing site like this one, there are too many files that are uploaded to these sites that will violate the terms and agreements of Google Adsense. You can't control what others upload to these sites. However, if you create your own download site and upload all the files yourself this one could be possible. However, you'll need to prove to Google that you have permission from all the books, files, films or whatever you want to offer on your site. When you use Google Adsense there are very strict terms and agreements that you must follow in order to qualify for this account. If you violate any of these terms or agreements then your account will be suspended and you'll lose the money in your account.