Should I tip the pourers in a tasting room?

Hello there! I'm Dr. Vinifera, but you can call me Vinny. Ask me your toughest wine questions, from the fine points of etiquette to the science of winemaking. And don't worry, I'm no wine snob—you can also ask me those "dumb questions" you're too embarrased to ask your wine geek friends! I hope you find my answers educational, empowering and even amusing. And don't forget to check out my most asked questions and my full archives for all my Q&A classics.
Dear Dr. Vinny,
When visiting wineries, is it appropriate (or required) to tip the people who pour? Does the answer vary by locale?
—P.Q., Hillsborough, N.J.
Dear P.Q.,
I took a consensus among tasters and tasting-room employees alike from different regions, and the simple answer is that it's not necessary. Most tasting rooms charge a fee so that you can taste guilt-free. But a tip—especially when you've gotten great service—is always appreciated. So if you have spectacular service, if you're with a large group, or if you're served additional wine (beyond the fixed list), please consider tipping.
—Dr. Vinny