I'm a trader by day, and I find it difficult not to bet on Ronda Rousey to enter the Royal rumble on a mobility scooter @ +5500. But I'm not black out drunk at my day job, most the time anyway.
I know loads of guys who gamble professionally, mostly poker, but some trading on UK betting exchanges (which I do too, but a lot lower volume). They make a lot of money, but they are pretty much always working, and every holiday with them is based around poker tournaments. You can see it wears on them, so I don't envy them at all.
This forum is probably the best I've seen for betting, you get good input and a lot of guys do some great research which I simply think one person could not do themselves. You have to sift through the occasional #superelite argument, and Barry (best just to block him), but this forum has done nothing but good things to my BR.