I've worked at good and bad companies that do this, and their number one target (in enterprise software at least) tends to be the SDR team - Sales Development Representatives. These are usually fresh college grads or salespeople with limited experience that are excited to take their first steps into the world of tech sales.

I've seen companies initiate SPIFF programs and other competitions as a way to incentivize new employees, sometimes with only days of experience, to post a glowing review of their new employer.

Before you work for a company, make sure to filter on Glassdoor and understand how many positive reviews are coming from "Sales Development" and "Business Development" reps. Don't get me wrong, their opinions are valid, but if you see a flood of very generic 5-star reviews, that's not a good sign.