I think you need a domain that says what it is. Something you can sit down and send targeted sales letters. A domain like say OhioFlorists.com is easy to market.
Any keyword com or net with a high search total and high bids can be resold, because the market already exists. If you do your research you can buy them at cost.
But 3 char .com's will always be a commodity because there's only so many available and they're all registered.