It's all about the headline. A good headline will generate twice the upvotes in half the time. A lot of great stories never make it to the front page because the headlines are terrible.
Are you serious? (Mostly) Every upvote gives you a point of karma, every downvote takes one from you. Various facilities in HN have a threshold karma requirement, so when you've garnered enough upvotes (and hence karma) these facilities become available to you.
Stories and comments are sorted so that more upvotes push them higher, but they drop over time. Sort order is votes divided some exponential of time, so newer comments/stories appear higher so they have a chance to get noticed, but then drop to the order dictated entirely by votes after a suitable length of time.
All this is in the FAQs, but you said you didn't understand, so I thought I'd provide a high-level summary.
OK, so the market is saturated with similar apps. - however - it is still very early days with regards to internet radio and there is still plenty of opportunity and room for innovation and indeed, profit. More so, if done in a collaborative, non profit kind of way...if you get me..
Existing apps. are by no means perfect - Last.fm makes very obvious recommendations - I type in Jimi Hendrix and it plays me The Doors. I want it to play me Space Guitar by Johnny Guitar Watson but I didn't know that. Or perhaps some 60's Jap Rock...
So there's that and there's also the apps. that just focus on indie/unsigned music. I think they are leaving out a lot of the good stuff by limiting themselves to offering just unsigned material.
Why do ideas that change the world always create wealth?
Mozilla, Miro, Wikipedia....the list goes on. If it was inverse - i.e. the number of non-profits outweighed the number of for-profits - I am quite certain you'd see a bigger change in the world.
