I'm a really big fan of Bandcamp, but after explaining how it works recently to a few aspiring and emerging artists their eyes all seemed to light up at the same point in the conversation - "you can also sell your music on there", and it's got me worried that they're missing the true value of it.
I must have downloaded well over 200 different projects on Bandcamp in the past year which means I've given out my email address and post code to all of those people, and so far only two artists have stayed in touch. [Disclaimer: the rest of this post will probably be boring if you're not a new artist or you know what you're doing.]
If I were an unknown or emerging artist looking to generate a fan base independently, I would create a couple of amazing projects and plan to give them away for free on Bandcamp. The first thing I would do is make a hit list of influential DJs, bloggers and journalists I think would like it, then approach them all with it personally well in advance of releasing it, letting them know when it will come out and asking for their support. Then when the release date came around I would send them the Bandcamp link and info (personally), and ask them to help me spread the word.
Once the email addresses started to come through I would sign up for a mailing list provider (YMLP is the cheapest & easiest) and email everyone who downloaded my music a thank you. I would also stay in touch with them on a monthly basis about what I'm up to - live shows, music, videos, photos, things that inspire me etc so that I could build a relationship with them - not just emailing them when I wanted something.
Then when I had another project to put out I would repeat exactly what I did last time, only this time I could also let my new found fans know in advance I would have a new project available soon and I'd love their support to spread the word. Once I started to get a decent sized list together and a buzz I would group fans by country/ town and use them to help me book a tour so I could make some cash. I might release a project for sale later on as a pay what you want (of course setting a minimum amount) and hope that 10-20% of my hefty new found fan base would be willing to support and pay for it. When the time came I would also be able to use my play counts/downloads/email addresses etc as leverage when talking to labels who approached me - after all if I could do all of this myself they'd have to bring a decent offer to the table to make it worth it.
What I definitely wouldn't do is put out a half finished, just ok new project every week and spam random bloggers who've never heard of me hoping they'd put it up. I also wouldn't upload my old album that wasn't very well received and try to get people to pay for it. Or be really short-sited and start trying to sell to my fan base when it reached 1000 to try and make £1000 (10% paying £10 each), when if I did my best to get it up to 10-15000 strong I might make £10,000 (10% paying £10 each).
I suppose my thinking is this - ask yourself how much a record label would pay for and invest in your project right now. If that number isn't high because you're a new artist, then use Bandcamp to help get yourself to the point where they will be making you offers, and then ask yourself if you really need them.