Depends on what kind of little people. The particularly prescriptive ones - where it's already clear that they are a pirate/firefighter/doctor/child/swimmer generally don't last very long as it's harder to work imagination into it.
The basic people that have a face and body are far more versatile, and generally lead to more elaborate play, so tend to get more action.

That's what I've observed over the last 10 years of working with kids.