And just a little clarification:

One of the rules is to re-steem their post.

Their original post (which is the one I linked to) is too old to re-steem, but you can re-steem the newer announcement instead: https://steemit.com/blocktradesworldcup/@worldcup-russia/you-still-have-time-join-the-blocktrades-world-cup-and-win-2-000-sbd-in-prizes