I have to say, the best compliments I get are off cam. My regular high tippers routinely let me know their weekend plans so I know when to be around or not. Because Streamate is not as tip-based, this makes a huge difference for me.
My favorite though was a pleasant private session on streamate, which does not do offline tips, where my guest was polite but reserved. I logged into MFC a few days later (curiously, I like to look at my horrible cam score), and I found he had bothered to look me up and send me a tip.
Guys tell me I'm pretty all day long. Going out of your way, way after the fact, to tip extra for a show is very flattering.
I'm not a money grubber, but if I want to hear how pretty/smart/funny I am, I just go to a bar.