Trading the Betfair markets is most definitely a genuine earning opportunity and for those who are determined and committed enough, it certainly can and does replace a full time job. And then some.
Whenever you see two numbers separated by a slash, i.e. 10/1, this is a fractional betting odd. Fractional odds allow you to calculate how much money you will win on your bet in comparison to you stake. The number on the right(e.g. 10) is how much you will win. The number on the left is how much you need to stake.