Too much competition... and patience, you need LOTS of it... do you hate stupid people? or rather, do you see stupid people? if yes, then this job is not for you.
OR you do one of those half n half things. These days its getting very popular. Basically you give half of what you get to the home buyer, in exchange for doing nothing. So basically you wont show them any house or help them with anything, they will just give your name to the selling agent as their Realtor, you will just collect the money and split 1/2 and 1/2 with the buyer. You can keep your full time job and do this on the side. however, if I am not mistaken, its ILLEGAL