come racing 
I've found that when I tell people away from the markets that I have bots for Horse Racing, they often ask to buy them on the spot...
if it's like that for me must be the same for others. I just describe myself as a bookie these days unless the person knows more than average about betting and it gets the point across without too much follow-up, people understand that generally bookies make money and that the price they get on at is in their favour. Compare that with "full time gambler" and you'll be stuck in that chat for 10+ mins