Its not just open and shut, there's a bit of work involved ...
From their T&Cs (check out their site for full terms)
Open an account with EurosportBET and place your first bet. You will receive a FREE bet matching its amount up to £50
Place 10 further bets by using the money in the main balance and receive an extra FREE Bet matching their average stake up to £25
The process will be repeated once again as you place 10 more bets until you have received a total of 3 FREE bets of a total amount up to £100
"The FREE bets are credited within 24 hours, therefore if you place your bet today the FREE bet might not be available on your Free Balance before tomorrow"