I kinda go by the same rule..
I mean, if you're running late because things beyond your control then let the person know. If the appointment can be kept, awesome...
Today I had a half hour. I'm back east where those exist.. The guy was 21 minutes late!
He didn't have a hobby phone, apparently his crappy one had just died...
He has tons of history and perfect refs...
I started the email at 2:18. I sent it at 2:20. I sat down and turned the tv on. Knock, knock.
I canceled the meeting. I had someone else at 3.. He was like, no apology, no nothing. Blamed it on construction. And the directions that I gave him. One, I didn't give him any directions. Two, because he knew where the hotel was.
I asked what we should do at this point.. He says, "Oh I see.. You want money."
Well, I have been standing at the door for the past 20 minutes so to not have you knock and wait.
He gave me $20.
It was a pretty rad experience.