One out of three people admit that they have skipped out on a tip because of bad service, but that's nothing compared to how many people who just don't tip!

A survey by CouponCabin found that tipping habits are far from universal, and can vary depending on everything from the economy to the service.

One in five people say they tip less when the economy is down, even if they were happy with the service.

87% of Americans say they feel obligated to leave a tip at a restaurant, which means that one in EIGHT people don't feel like they need to TIP AT ALL.

One in three people don't feel obligated to tip their hairstylist.  Half of us don't think we need to tip a valet, and four out of five people think it's okay to not tip the restroom attendant.

I don't pretend to know all of the tipping rules, but I will say that it takes an absolutely horrible experience for me to leave nothing . . . and even then I feel bad!