Pros
They're contained to their cage
Their accessories and food are less expensive than many other pets
They're fun to watch the first 6-12 months.

Cons
They smell, especially if you don't clean out their cage every few days
They get old and slow and boring their 2nd year of life and the kids lose interest in helping.

Another Pro
They only live a couple years so the miserable 2nd year doesn't last forever.

Another Con
They're heart broken when it dies even though they haven't been interested in it for a long time.