It's peanut for Casino and sportsbook. A large casino should have millions of dollars of bankrolls.
For some, $7000 is obviously a lot of money, so some are surprised that certain companies spend so much on advertising on this forum. Personally, I wouldn't be surprised if I found out that their direct income from advertising on this forum exceeds their investment many times over - because only one passionate player with a slightly bigger wallet is enough to pay for the campaign for the whole week, or maybe even for the whole month.
I was not talking about individuals but sportsbook and casinos. The amount of money they make is enormous. Those of us who are not big gamblers may feel that how do the casino survives but when a casino with millions of users depositing even $100 per week, it's a billion dollar income even considering some lose to pay the winners. We had many scam accusations and they were settled later. Few of them I can remember. Once was over 335 BTC and another one was over 1500 LTC. Fact is, we are only seeing those are coming in public but they should have many more big clients like these.
I think with bitcointalk for some of them it's a cheaper advertising option. When casinos sponsor an international club or event, they spend millions.