Blood Letting?

I was reminded today of one of the last times I went to give blood. I was waiting for my turn in the lobby area, and a normal-looking, middle-aged man walks in asking to get his blood drawn. No, he says, he's not there to give a pint for someone else. He's just there to get some of his taken out. He mumbled something about health reasons. Perhaps even odder, I suppose, is that they did it!

I haven't researched it or anything, but do people do that kind of thing? I thought that went out of vogue centuries ago...