As someone that creates content (although not musical) I really think the ability to buy and sell mixtapes would benefit the site greatly. It would also create an incentive for non-LB artists to sign up.
Edit:
I take that back. Just spent a little while longer on the site and realised you've finally gone and killed it. It's sad for me to see as I've been on here for what? A decade? I guess everything has to die eventually. If anyone can let me know where the best place to hang out is now that would be great.