So I had a bad experience with "service" last week. I'm happy to report that I've had many examples of good service since.
Apart from the hotel receptionists, taxi drivers and waiters who've been genuinely helpful, I've been pleasantly surprised by the honest advice given in shops in San Francisco. More than once I've been told "I wouldn't by that here. You'll get a better deal a few doors down."
This happened when enquiring about sim cards, fruit, and tickets for guided tours.