I've also seen for campaigns that pay participants with eth directly but that's for me personally less surprise and less challenging. just look at ico who shared his prize with a small coin and if we are lucky in following the project and the coin price is very high we will get many prizes that I like to follow the campaign even though it was quite long to wait for the prize to come. but if the price drops while handing out the prize it is already the risk of a bounty hunter