Is there a smart contract where you can create a crowd funding campaign. Say I wanted to raise 1000 ETH within 30 days or X number of blocks. If the 1000 eth goal isn't reached, it will return all the funds back to the users that sent it to my smart contract. Does something like this exists? And what issues might one run into when doing something like this?
I'm curious to how funds are returned. Say if 10000 addresses sent me random amounts of eth. Wouldn't gas cost alot as it would have to loop through all those 10000 addresses to do a refund?