I'd never even seen a full episode until a couple of weeks ago. I'm in the UK so it's not as popular/advertised over here. I borrowed the first two seasons on DVD from my friend and when I'd finished them I ordered the third, which I finished last night. I went through the entire three seasons in about 2 weeks! I love it.
I knew who Jared was, but had no idea who Jensen was...so he was a very pleasant discovery