I saw this on TV, so I thought I'd check it out. This offer says you'll get a yield of 180 pounds of tomatoes for just $10. The offer sells you 3 of their Tomato Trees and, as a bonus, you get three early hybrid tomato (do they run on ethanol?) plants as well.
Of course, you have to plant them, water them, make sure bugs and critters don't get to them, but, with tomatoes running about $2/pound at the local supermarket, even if you only get a crop yield of 20 pounds, you're going to be way ahead.
A little gardening can go a long way. This sounds like an OK deal. Tomatoes are not cheap, but they are yummy. Growing your own is pretty easy, and besides, you can say "crop yield" and impress your eco-friendly associates.