Online distribution of games

Hi,

I'm currently looking into developing my own independent
game development. But to "improve" my estimations I need
some numbers. Perhaps anyone in here can help me ?

1. What is the average conversion number of downloads <->
sold copies ? I've read something about 1%...

2. What numbers can be estimated for a high quality game ?

3. What is the best way to make that game public ? Who should
I contact to get it into the major online gaming websites ?

4. What online bandwidth would I need ? What's the average
bandwidth used by an independent game developer ?

Well, I think that's all for now.

Stefan Maton