Binary betting is very poor value - the spread you pay is ridiculous.
For instance if you go each way on a bet - i.e. make a bet and also bet the opposite direction so that each win cancels out the others loss, then you lose 25% of your total stake just to the spread. So you'll only ever walk away with 75% of your money whatever happens in this scenario.
That's just shocking value for money and you would have to have a serious edge to make it long term.