Shit-ton, despite sounding like a measure of mass, is actually a measure of volume. In other words - a shit-ton is the volume occupied by a ton (mass) of shit.
(On a tour of a brewery) "On our left, we have our primary fermenters. Each fermenter has the capacity of 2.3 shit-tons, which is equivalent to the amount of beer drunk every second in the United States"
An actual unit of measurement. Just below an ass-load and right above a fuck-load. Consider two million views for a YouTube video in two days as an example.
"...but this video did get just under two million views in about two days-which is what scientists and scholars refer to as a shit-ton of views."
-Ray William Johnson from the =3 episode "WANNA FIGHT?"