Ok, so my last thread about marketing to greeks didn't turn out the way I had hoped...

(If you really want to read it, see "where do you buy your t-shirts" in the greek life forum...it got a little nasty). So I'm going to rephrase my question and try again.
Here's the situation: I work for an advertising agency which also has a division that sells promotional/imprinted items (like party favors--can huggers, coolers, cups, hats, etc.) and T-shirts. We are in a college town, so lately we have been getting some business from fraternities and sororities. Because we have a very low overhead and a good relationship with our suppliers, we are able to beat our competitors prices by several dollars per shirt. (I'm not saying this to brag or advertise, just stating the facts.) My boss has asked me, because I am the most recent college graduate and because I am a member of a GLO and a chapter advisor, to research how we can better market ourselves to the greek community. We already know that many "greek- friendly" businesses take advantage of college students because they order a high volume of shirts & favors and are often uneducated about the huge profit margins that the companies are making...sometimes 200% profit.
So...we want to know what is the best way to get our name out to the greek community here at the local University as well as other schools in the region. Also, what do you look for in a vendor... low prices? samples? freebies? a website? How do you make your decision about where to purchase your shirts & party favors? Do you favor a local company or do you go with a bigger, national company either on-line, by catalog or through a campus representative?
Any information you could give me would be most appreciated. Please note that I am not asking where I should buy shirts or advertising for my company (I didn't even mention our name here). Also, I am NOT a salesperson. I'm in the art department. So even if I were advertising, I don't make a commission. Just wanted to clarify that.
Thanks for reading and I am looking forward to hearing your opinions!