[ansel12]

People don’t tip their plumber when he crawls through the mud under their house in the winter at 10pm, or 10am for that matter, but they are afraid not to tip a waitress.

[1Old Pro]

People don’t tip their plumber when he crawls through the mud under their house in the winter at 10pm, or 10am for that matter,

I do. Even for regular work.

[fr_freak]

People don’t tip their plumber when he crawls through the mud under their house in the winter at 10pm, or 10am for that matter, but they are afraid not to tip a waitress.

That's because the plumber will bill you at something like $60/hr or more, while the waitress makes $3/hr plus tips.