These bookmakers online will give you £10 free bets for making a first bet with them.
TitanBet - Risk Free £10 bet for Mobile - At TitanBet you can grab a free risk free tenner bet when you make your first bet on a mobile device. Odds of the bet have to be 1.8 or over.
Risk Free Mobile bet at Netbet.com - A £10 risk free bet is there for the taking at NetBet.com. Visit m.netbet via the link above and place a bet of at least £10 for a free £10 bet in return if it loses.
Unibet - Risk Free £10 bet for Mobile - Another no lose bet promotion, similar to the titanbet offer. You place your first bet on your mobile device and if it loses get a free £10 bonus bet. No odds restrictions on the bet you place. For UK/Ire customers only.
Totesport - Bet £5 get a £10 Free bet - Sign up for a new account at Totesport, place a £5 bet on any sport market and receive, once settled, a free £10 bet instantly.