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Facebook apps have been pulling in money already by being sold off, but how do you find a buyer for your work? Appmrkt looks to help you with this task. Just join the site (they require this to keep fraud to a minimum), and you're all set to list your app for sale, or find one that appeals to you.
The site is in "Alpha mode" so they do warn of possible hiccups, but it should be usable.
Disclosure: Mashable runs the Web 2.0 Marketplace, which also supports the sale of Facebook Apps and services.
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