Working together with people on the whole thing is always win aswell. For example, the pictures. Go to some art communities like Deviantart. Look around for some pictures. Ask the artist if you can use it. 9.9 times out of ten, they will say "yes". They're pretty much all very nice & motivated people. And you both win, he might go spread your music around, you spread their art. And believe me, some of them make some fantastic work!
Social media has done a lot of good for artists. But not always. You'll have to do a lot of work, or you'll get drowned by fellows. You might have better music and such, but if someone's really popular, you'll have to step up. As most posts already said, soft advertising by giving feedback does a very very good job. But it takes alot of time.
It's true, spamming with "look at my song" ain't really good, but there are times it works. Earlier, I was browsing through Doctor P's Facebook page, and someone posted a (relatively) related song. And damn, he got a lot of views from that, and a lot of comments on Soundcloud as well.
Summing up. You have to figure out a strategy, have friends maybe help you, work together with people. Power in numbers! But most of all, enjoy making your stuff. Don't let down because your fellow musician had 3 times the views in the same amount of time on a worse track (<- subjective anyways).

