Interface vendors contacting after the event

I recently went to the Interface 08 event held at the Washington State Convention and Trade Center and in the month since I attended I have received more unsolicited calls from vendors than I did in the previous 11 months. Only 2 have specifically identified that they found me because of participation in the Interface event, but I have to assume that means others have access to that data too. Given that the event cost nothing, I suppose I should not be surprised by them selling your data, or making it available as it where; but I am surprised to be getting the calls.

The even was pretty nice and I did find a few items that I do plan on following up on in this fiscal, but I was frustrated to have cold calls for products that I didn't even have and interest in. I made it to every booth that had products or services that I was interested in, so feel free to not contact me.