Thousands of domain names expire every day. The reasons are different. Some owners forgot to renew the domains, some just don't want them anymore or they moved on to other projects. For most people these so called Expired Domains don't have any value. They just see a bunch of Domain Names someone else deleted and move on, but for the people who know about SEO or the value of good Backlinks, Expired Domain Names are money just waiting to get picked up from the street. The only problem is to separate the good ones from the bad ones. That is where comes into play.
Thanks for the great review on domain flipping. I could definitely see myself getting into domain flipping down the road. I constantly find myself thinking of domains that are probably worth buying. But the way you have presented and analyzed which keywords get the most page views makes it more like long term investing. I also never considered trying to market the domain names or that Adsense money could be generated. Thanks for sharing and good luck with your domains!

You can turn then into content sites, set up an actual website, or try to sell that site elsewhere. You may even luck out by selling a site that's up and running and full of great content already. In this case, you can ask a higher price. Or, you can set up a shared hosting or direct hosting website. Shared hosting and direct hosting websites can be profitable too.

it can be profitable,i'm selling domains and i can tell you that all providers loose money selling domains,we compesate it with  hosting plans but if you look just domain selling where providers buying domain for 7$-10$ and selling it for 0.99$-5$ ...well like say we compesate this with web hosting plans and other services,also on when some one renew domain but since even renewal is done mostly using cupons...than giving free domain with web hosting is best solutions.Well like i say it can be profitable if you want work with domain,buying domains for 0.99$ and than work with it and you can earn nice money.
There’s an important distinction to make here between domain flipping and website flipping. The latter mainly refers to buying and selling full websites. By full websites, I mean websites that actually have content and more often than not have traffic and revenue. When buying and selling websites, the domain name matters less as the main value there is the content, traffic, revenue, history/reputation, sustainability and growth opportunities. The same can’t be said for domain names where you’re just selling “the name” and hence it’s all that really matters.