Roobet has special promotions for the upcoming World Cup. Check this
Link out
Put $30+ outright bet on the world cup winner and each time your choose country win, you will receive $5 in term of free bet so basically thats 6 times to win to get your bet back so pick one wisely. Brazil, Argentina and Germany is pretty much the top favourites for now
Also don't forget they also have a promotion about the top scorer on World Cup [1] actually it's pretty similar, but just different condition. In this promotion you're only need to put minimum of $25 and every goal by the player we've choose will receive $5 free bet.
I think combining both promotion is really a good idea, Brazil is high likely will qualify until final since they have a lot good players. Even though Brazil will face a strong country, they're still more stronger right now.
[1]
https://promotions.roobet.com/promotions/football-world-cup-top-goalscorer-bonus