It’s essentially a place for people to sell their own art; art being books, music, photos, paintings, etc. They get to set their own price, and offerings are made in digital or physical format. So you can order a book and have it come in paperback, or download if pdf, html, text, or whatever the author wants. For visual art you can download it, or have it come on CD. The same for music.
Upon cursory inspection, most of the songs are about a buck, and the cd’s about $5. The artwork averages about $5 per picture, though some are free, and some are more than $25. CD’s are more obviously.
They also enable the artist in a variety of ways. Their newest thing is calendars. If you have 12 pictures you’re selling, you can have them sold as a calendar, and lulu.com takes care of the creation. They take a cut obviously, but the artist’s cut is pure profit, just from the effort of filling out the form and putting up the pictures.
This is one of the coolest ideas I’ve seen online in a while. It’s much like mp3.com was, but for a wider range of art. I’ve already used it to get some nice artwork for a website.