The issue here is that the website as far as I can tell offers no advantage over posting here.
Here, people often (not in all cases) post with some financial benefit such as signature advertising or to build brand reputation for their own crypto ventures.
However, your site has just 5 members.
If you really are going to host a competition to launch the website you'll need to consider choosing an escrow to hold the 5
BTC and also choosing independent escrows to select the winners or it would be very easy to falsify this. Also when the competition is over, what incentive will there be for people to continue posting? These questions you have to understand and answer or this will not work as a project, and this is coming from experience
If you want this website to be a success then it has to offer something different to this forum - Best of luck!