Why? If I really enjoyed it and had money, I'd tip, but I'd probably not speak. Somewhat shy, and have been burned too many times by creating an opening for someone to take advantage of me. If a musician is playing I might catch their eye & smile, and move on. Online, rather than in person, (especially when I know the author/artist) I might be more likely to say something -- but I'm not good at thinking of things to speak when on the spot. And it's not so much that I figure I'll look stupid and that bothers me, but that I'll _be_ stupid and be wasting the time of the person I want to commend.

I saw a paypal comment above -- I know once of all the times I've donated via paypal I've elected to pay a bit more so that the recipient would get the full amount -- but I'm wondering if I selected the wrong radio-button that time -- I think if you choose "gift" they don't take their cut.