I saw this site last week or maybe the week before, and to be honest, I was put-off by the obnoxiousness of trying to get people to buy the "least popular" t-shirt. To me, it came across as you trying to unload your shittiest product through some clever trick. It had a Zynga-esque feel to it, and I didn't like it at all. The fact you give a clue like "this was the worst selling t-shirt in the last hour" makes me feel like you're tricking me, and I'd rather do business with someone else than risk getting played or ripped off. Sorry, but that's the feeling I get when I see this site.

If you want some additional feedback:

Instead of the gimmicky "you lose I win", I think you need to make it some sort of win-win type gimmick. Like the price goes down the more people buy it, and whoever buys it earlier will get some money back on their next purchase.

You need to make the "game" shorter, I don't have patience to wait a week until I know if I "won".

$25 is something I would pay if the t-shirts were good quality, like American Apparel, but you didn't list the manufacturer.

You need a lot more designs. I was looking for the button for additional designs, but I finally figured out you only have those 5. If I hate all 5 of them, then I won't likely remember your site, and won't come back.