It can be done. However it's very difficult (from what I've heard). You need to find low cost keywords to bid on, get traffic to your site showing higher paying keywords, and then hopefully you will make a profit. I'm not sure if it will be the best option for most people. Unless you are very experienced with Adwords and can constantly monitor your campaigns you stand a large chance of losing money rather than gaining money. Also keep in mind that Google has a Quality rating for Adwords advertiser's landing pages. If they deem that your page/site you are advertising for doesn't meet their quality standards you will have to pay a premium to advertise, increasing the cost of your clicks. Making it even harder to turn a profit. It's an attempt by them to make MFA arbitrage sites less profitable and even non-viable.