This topic has been discussed on MM many times. I think the conclusion is that its a waste of business card.
- Photographer sees hot chick, passes out business cards; most girls will play it off as a weirdo trying to "hook up" and use the "I'm a photographer" pick up line.
I would try this technique but most times if they show interest I'll charge them, which is kinda rude since your approaching them. Kinda like a model emailing you saying, "Hey I love your work, my rates are..."
Well, that's not much different than asking a MM model to do a shoot ... they are a very flaky group on average even if there are some who are professional. But in any case, some discussants on MM claim to have made some good contacts. As for pay, there are often situations where one would like to try out an idea without paying or being paid. Heck, I've got some locations at UCSB that are just dying for a couple of co-ed's to pose and the place is loaded with 'em so I'm probably going to try some cold calls when I'm out for lunch. Heck, maybe I'll do a calendar!