When doing a free t-shirt promotion, it is better to make the wearer look good rather than make the brand stand out the most. Then, user will wear the shirt more in more prominent places.
Thus, it follows that more brand promotion will occur if it makes the user look better. So, if you have the money to give away free t-shirts, then spend a few extra dollars to ensure that initial batch of t-shirts gets used well.
Caveat: The uber-fans will wear anything.
~ Danial Goodwin ~