Injecting someone else's red blood cells = vampire.
EPO isn't injecting other people's blood. And even with transfusion-based doping, it may be the athlete's own blood, and that can't be detected, other than saying "Well, he has a lot of red blood cells."
EPO is a dirty little secret. It doesn't get the press that steroids do, and it's a whole lot easier to beat the EPO tests than the steroid tests.
I don't have the link handy, but read a quote from a professional cyclist, who said that he kept telling himself that EPO wasn't as common in cycling as everyone thought... until amateur cyclists started easily passing him up long hills. And that was something like 10 or 15 years ago.
EPO testing is much more tricky, and much less reliable than steroid testing, and it's a whole lot easier to get away with. So, people do it, but it's never caught the national attention like steroids. It's been found in pretty much every sport where testing is done and cardio is involved, it's a lot more prevalent than most people think.