Pretty sure this will discourage most of the downloaders even though this somewhat encourages some uploaders to upload due to the paypout is good. But if no one uses this service to download stuff, even the payout is awesome, uploaders will not make any profits (Cuz uploaders make money through downloaders, who download their stuff) and this is due to the fact that
1) your filehost is just established and not a lot of people recognize that. In addition, there is no sure way that this filehost is stable and will run for years.
2) Not a lot of people use this filehost. That is, not a lot of uploaders use this service, which means there isn't a lot of stuff to download. Remember, downloaders tend to buy premium account if there is a lot of stuff for them to download. They want to pay what they deserve in return.
3) Remember reputation gets built up slowly and this cannot be done within a day or a month. Due to the speed restriction, surely that people try it once and never gonna use it again because the first impression they get from zooupload is bad (crawling speed) compared to other filehost. So first impression is really important.
You might want to consider the strategy Megauplod or Filesonic use in advertising.