yeah nah that shouldn't be acceptable. it's only ever happened to me once and I never tipped them again. I'm not sure how someone can run a page and not acknowledge literally being given money, especially when it's for nothing and not a specific request. The weird thing when it happened to me was it wasn't even a very big page, in which case you could maybe see it getting lost
I haven't been on MFC in years but back then these knuckleheads fall in love with cam whores and want to impress the 300-400 guys in the room by "bidding" on the model's stupid raffle. I don't know if this guy had money or maxed out his credit cards but I think it was more about impressing people in the room than it was about getting a HJ. That's how I saw it anyways.