start up a Bitcoin lottery!

[jootjejodel]

How can you make a bitcoin lottery provable fair?
Why is it that many bitcoin lotteries are not working anymore?


And an unrealated question what happened to this website:
http://btcmultiplier.com/
"We were victims of a scammer who double-spent us out of existence."
What do they mean with this?

[thecoinjournal]

Because they didn't require at least 1 confirmation for the deposit.