Bandcamp provides "fast, dependable streaming and downloads of your entire catalog, adorn your tracks with all the metadata they need to sail into iTunes," and assists with your branding and marketing of your music.
"Sonicbids is the leading platform for bands to get gigs and promoters to book a band online." As the developer described it, it's like ebay--an online marketplace eBay connects artists and bands of all kinds with music promoters. The site has a blog with marketing ideas.