Just spotted this cracking offer at unibet, simply place bets totalling £250 on the french open and they will give you a £50 free bet for the world cup which kicks off in a little over a weeks time.
You'll need to opt-in first, you can find it advertised on their sportsbook homepage. After having a quick look, the in-play odds look pretty decent so you shouldn't have too much trouble finding some good value bets for this.
Betfair also have a "bet £2 get £2 free" on their blackjack side games at the moment, again this can be found on the right of the exchange homepage.
