Nearly 16m bets were placed on Betfair via mobile phones in Q2 2012

"The Euro 2012 football championships helped Betfair post a jump in sales, with soaring numbers of people using mobile phones to place bets.
The online gaming group saw revenues up 13% to £91.6m in the three months to 31 July. UK growth was up 23%.
The number of bets using mobile phones rose 114%, while revenues generated were up 98%, a trading update revealed.
[...]
The number of bets using mobile phones increased by 114% to 15.8 million, with revenue up 98% to £8.2m during the quarter."

Source:  BBC News, 10th September 2012