I do lots of offline SEO for clients, and it's really easy to analyze those sort of income levels. I know the customer makes per sale and I know the time factor and SEO investment factor. But how do you guys go about getting a strong feel for whether an adsense site is profitable? My goal is to make sites have a minimum of $50 a day earning potential but I am not 100% sure on how to analyze this on keywords / niches before starting the site. I had one a ways back that made 500 month but got slapped by Google and I let it go. Anyone have some good basic tips?