Adwords is very good for selling products and lead generation, but it's very hard to buy clicks from Adwords and then arbitrage them on an ad supported site. If you do simple math, you'll see how hard it is to make money by doing this. Let's say you pay $1 a click. For each person that you pay to visit your site, you have to earn more than what you paid. Some people are very sophisticated at this and have found a way of buying very inexpensive clicks and then sending them to pages with high earnings, but in general, this is very tough to do with an ad supported site. Like I said, AdWords work really well when you have a product or service to sell and the margin can support covering the price you pay per click and converts at a rate that makes money.