Or they could be outright lying. Like HealthTap. If you read their reviews on glassdoor, every 10-15 you get an honest review. And if you google the ceo, he goes through dev teams like tissue, both in this and in prior startups. But the majority of reviews are glowing.

contrast this: http://www.glassdoor.com/Reviews/HealthTap-Reviews-E453567.h...

to

http://www.glassdoor.com/Reviews/Employee-Review-HealthTap-R...

or

http://www.glassdoor.com/Reviews/Employee-Review-HealthTap-R...

or

http://www.glassdoor.com/Reviews/Employee-Review-HealthTap-R...

etc