I am fortunate enough to help a lot of clothing companies create awesome sites with my company Double Dragon Studios. While I am in there putting in all the code I also get a chance to look at all their web statistics. The one thing that surprised me the most was how little internet marketing a lot of these companies do and they still bring in a lot of sales.
What I see is most of the traffic comming from are simple google searches with the clothing companies name. So most of their traffic comes from people seeing their brand in stores and then searching them on the internet. This is one of the reasons why I think tags are very important to be well designed and have your internet address on them. They won’t always make the purchase at that store and might go online and order directly from you.