Okay, it appears that I'm going to be the only dissenting opinion here.
The discussion around karma here is all centered on the SFW side of reddit, it appears. I used to operate on the NSFW side of reddit to find sexual partners. After I would make a post explaining the kind of connection I wanted to make, I would get like 150 offers over the course of 3 days, both over direct messages (orangered inbox) and chat requests (chattit).
I would only respond to users who had any sort of karma, post history, or more than just a few months on their account. My thought process was that I don't want to meet people who are 100% lurkers, I would favor people who had comment histories on normal subs and were contributing members in those communities (gave me hope they would be interesting conversationalists on the date), and I wanted to see some longevity in the account so that there was a clear sense of the decorum of old reddit versus all the sally-come-lately users.
ETA: I suspect that I was getting so many offers because I myself had made several submissions (lending to my own non-zero karma score) both text and photo and I had a long-standing account. I think I would have been viewed skeptically by everyone if my account was 3 days old and I had zero content, but was trawling for sex. That's how men show up with 2 kidneys but leave with 1 in the morning.