I have a gallery there since last year. I have sold only 4 shirts so far. The problem is that hardly anybody knows about the site. T-Shirt Monster needs to do more advertising. If you google Canadian T-Shirts, they are nowhere on the radar. They need to increase their web presence and get more traffic to their site.
Aside from that, I love their simple to use and clean gallery setup. They have great quality t-shirts made in Canada and USA. They also have a good affiliate referral plan with lots of promotional tools (flash banners, image links, text links etc).
As always the best thing is it is completely free so you have nothing to lose by trying it out yourself.
Has anyone worked with T-Shirtmonster or sold anything through their site? 
