I'm considering to buy freebie sites looking to diversify earnings away from adsense, by getting affiliate revenue. I'm new to this type of sites, and wonder what should be the typical monthly profit multipe I should be looking at to pay. I've heard that the market is quite competitive, and users typical sign up for the first gift and then never come back. Is that true in general? Why don't they stick to the site? It'll be tough to always look for new customers. Thanks for any advice!