Ask HN: OK, I've started-up, now how do I continue-up?

At the beginning of this year I "soft launched" a video game recommendation service. I knew how to build the site and make it work, but I'm mystified by marketing (even if I had a million dollars to throw at marketing I wouldn't know where to throw it), so I applied to a bunch of incubators (including YC, of course), sure that one of them would pick up the project because recommendation services were pretty sexy last winter. Alas, they all declined, but the site kept chugging along. A few other opportunities came up that distracted me from it, but they've all either run their course or failed to pan out, so now I'm back to the game recommender. It's steadily grown to 670+ users who have contributed a total of 40,000+ ratings, but obviously that's not nearly enough users to attract a potential buy-out or partnership, or make affiliate links lucrative, or even support my clever original plan of serving ads specifically to users who the recommendation engine had determined would like each ad.

Meanwhile, just as I'm getting back to it, Penny Arcade has announced that they're launching a similar service. That quells my worries that "maybe there's just not a market for this", and (hopefully) the services are different enough that both could survive. Also on the bright side, the Penny Arcade announcement has given me a boost in activity from people who were reminded by the announcement that my service already existed, and presumably also from people saying "oh, that sounds neat! I wonder if there already is something like that..." and finding mine.

I'm sure there's a huge market for this service, and the internet is filled with video game forums that I'm sure would be interested -- the site was briefly mentioned (with a link) on the second page of an unrelated thread on NeoGAF and got over a hundred hits just from that one link. But all of those forums have a strict "no soliciting for your website" policy, and they won't even reply when I email them asking for their advertising rates. I'm gnashing my teeth walking through a market filled with millions of potential customers, but forbidden from mentioning my wares to any of them.

So, HN, please tell me: where do I go from here? On the one hand I think my startup is "successful" because it does what it was designed to do, and it's providing a useful service to me and a bunch of other users, but on the other hand it's growing at a glacial pace and it's not making any money.

Help!