I'm a huge fan of databases and I strongly believe I can money with them. Me and my friends are can write different kind of crawlers but I'm wondering, where do we start the work of selling databases? What are the most valuable databases on the market? In my head databases of doctors, dentists, etc. can be sold for good money. Or am I wrong? Please share me your thoughts.
Are you referring to mailing lists or are databases that include all company/personal information? If you're selling personal information, I don't think that's legal. If you're not selling the latter, what kind of database are you referring to?