I use Soundcloud. You upload your crappy track. Then people add comments to it like "cool bass drum!" and "I'm feelin' it!!" at points of their choosing as the track plays. And they they become your soundcloud follower and then you become theirs and then you get to listen to their crappy track and add comments like "great hi-hat" and "this is gonna SMASH IT" and then nothing whatsoever happens because - let's face it - you're just a load of people playing each other your crappy tracks in the dream that someone, somewhere with a massive cigar will call you, offer a $1000000000000 recording contract and free blowjobs for life. Happily, I'm not the above, of course. All my tracks are private: Soundcloud is a useful and inexpensive means for me to collate and send work clients, for them to preview the work and then download the music to the edit. I think this is the point about all these types of thing. Most people will look at them and think "that's shit, why would anyone want to do that?" but there will always be a percentage who get real value put of it. To me, LinkedIn, for example - is utterly pointless ("John added overhead projectors to his list of skills") but to certain people - apparently - like people in certain types of recruitment - it's actually invaluable.