For this reason alone, Betfair has no reason to ban or close your account when you should win. This is what Betfair first became famous for; peer-to-peer betting. Whilst the Exchange account won't be closed for winning, there is an additional commission rate.
On Browser:\n\n Select the odds next to the horse you want to bet on to place: This will then add it to your bet slip where you can select the each way box, add your stake and place your bet, using the 'Place Bet' button at the bottom of your slip.