Only desepered players would be moving from football to roulette. 
If football betting is based on expectations that your team will do well or that adversary team won't do well (with the help of reviews and historical stastics)(still need your analysing skills), Roulette is based on pure luck. All the strategies in Roulette are a kind of help to reduce damage rather than to help win more ; you have to spend a lot of money to learn about each of those strategies, test them, and choose your prefer.
Sometimes i thought iRoulette is only made for wealthy persons who don't really care if they lost all the bets .