One of my earliest songs, Radio Days Pt. 1 is in the new zombie adventure game on NewGrounds,
The Sagittarian 3!
I was first contacted about using that song in the game in April. Hyptosis, creator of the game, sent me a message asking for permission. Now, I hadn't touched my NewGrounds account in a while, and that message made me realize how worthwhile a system it can be. At the very least, lightning can strike twice, another artist can use another one of my songs in his movie/game, and that works out for me as well.
Also, quality of reviews aside, there's at least some brand of quantifiable feedback which, when used by someone knowledgeable and eloquent, can be very useful and encouraging.
P.S. I've already seen like 10 requests asking where Sagittarian 3 is.
Here's a live version of the song from my set at The Vault a few months ago.
Radio Days (Live from The Vault) by RhythmBastard