Pizza Delivery Guy Tip Protocol

I found out something yesterday that I did not even know!  Let's see if you know: how much do you tip the pizza delivery person? 

Is it 10%?  Is it a buck?  Did you know that there's a STANDARD amount?  

This all came up because of Reddit user jfastman, who posted a photo of a $1,453.95 pizza bill and a measly $10 tip. (FYI, that's not even one percent.)

He says that his friend received ten bucks in exchange for delivering 85 pies. The post sparked a flurry of conversation on proper tipping etiquette.

Mike Lynn, associate professor of consumer behavior at the Cornell Hotel School, suggested to CNNMoney that pizza delivery workers should be tipped a minimum of $2 per pizza. According to this math, the delivery worker in question should have gotten a $170 tip -- again, at a minimum.