Honestly, I think the best way to get exposure is just to get yourself involved in as many damn things as you can possibly get into. Game dev needs music? Go for it. New contest/activity in the audio forum? Take part. Animator needs a score? Offer your services. In all of the cases, make sure you deliver well, and be as charismatic and friendly as you can possibly be to whoever you're working with. On top of that, get involved in social networks, and regularly update them.
If you do all that, and of course assuming your music is good-quality, you'll get places. This method doesn't solely rely on you getting lucky. It works. Just be proactive, seek opportunities and try not to overload yourself with work. You'll gradually get more friends, contacts, and opportunities, all of which can translate to subscribers, fans, and recognition. I need to stress, though, that the key is being proactive. Do not just passively post music on a site and hope you'll get noticed, because that is when exposure is purely luck-based.
If you're still improving in your music and it isn't the standard you want it to be at yet, then Newgrounds is a great place to hone your talents and develop as a musician. Once you feel confident in your work, squeeze into any reliable-looking project you can find and, if you play your cards right, I have a feeling you'll be satisfied with the results.