There are many reasons. Read below for just a few:
*First and foremost, they are cute...awww, c'mon!!!
*Hamsters are relatively inexpensive animals to purchase and care for...at $5-$15 dollars per animal, they're a steal when compared to most larger pets.
*They are odorless, given that the owner keeps the cage clean.
*Hamsters require less human attention than most larger mammals...although they do require some in order to become and remain tame.
*They don't need to do their business outside in 38 below weather...
*They are highly interactive and entertaining...especially when one is experiencing a bout of insomnia at 3 a.m.