Without any other investments however there is no guarantee you can even pay out after 3 days. If I put in 1 BTC and the next guy puts in 0.03 BTC and that's it for 3 days, then I'm screwed. You have invested nothing into this other than some text in a post - no domain registration, no web design, nothing except some plain text on a forum. It would be so easy for you to take the coins and run.

People see these types of posts all the time, so expect a lot of cynical responses and mistrust.