a very important grammar thang. without it, many sentances would be very different.
with comma: I helped my uncle, jack, off his horse.
without comma: I helped my uncle jack off his horse.
Like the cocaine for Rednecks, they just can't stop coming to this economic bully. Walmart is run by fat stupid bald guys who hunt for badgers in their spare time and actually bought that stupid mounted fish that wriggles and sings.
"Hey mom! Look! a Badger Shooting game for only FIVE DOLLARS!!! Yippee!! YODELYODELYODEL!!!!"