profitable business idea - tshirts?

I've been toying with some possible business ideas and found some interesting info about t-shirts. One of my fave t-shirt sites is TShirtHell.com and apparently it is the most visited t-shirt site on the web. The guy who runs it is a millionaire and apparently that took less than 3 years. I'm not sure exactly how long that took. He started it in October 2001 with 10 designs and press from October of 2004 referred to him as a millionaire, so it happened somewhere along the way.

I also found some info on BustedTees.com, which I had never heard of. Seems Urban Outfitters has bought some of their designs in the past. They started in March 2004 and in an article from July 2005 they said they had sold 100,000 shirts online with a profit of $11 each and 75,000 shirts through retailers for a profit of $2 each. Wow. Now that's what I'm talking about.