I personally had a good day yesterday as well! I was down about 15 BTC~ but then ended up cashing out 52 BTC.
Honestly, the biggest trick to BVC is this: If you don't want to lose, then just don't quit while you're down. I know this sounds crazy as hell, but honestly. Some of the progressive jackpots are so big and technically if you just keep playing you will hit it. It's an emotional rollercoaster when you get thousands upon thousands of dollars in, but when it finally pays off you'll be happy as hell. You have to have nerves of steel to keep pushing when you're down, but eventually the odds will straighten you back out. (That is, unless the bots don't swoop in and shit on you)
It does sound crazy as hell, just trowing money and be persistent about it. But you know what they say, sometimes crazy works.