I used to use Glass door extensively to vet potential employers. After starting at one company however I realized the problem with this.
Regularly in meetings the head of HR (which they called "People") would encourage us to go leave 5 star reviews on Glass door to help with recruiting efforts. It was really spun as a way to help the company.
The problem though is that this company had some problems, things I would normally expect to see on glassdoor. Because of the way they encouraged it, glassdoor was flooded with 5 star reviews that made it impossible to find any negative ones.
Correct on the internal promotion - in addition to Companies compelling Glassdoor to confirm the Reviewer actually worked at the company. Often reviewers don’t respond, resulting in a removed review.
I researched this a lot because I noticed companies I had intimate knowledge of had any sub-4 star review disappear. I detailed the practices in another comment elsewhere;
https://news.ycombinator.com/item?id=24793383
Regularly in meetings the head of HR (which they called "People") would encourage us to go leave 5 star reviews on Glass door to help with recruiting efforts. It was really spun as a way to help the company.
The problem though is that this company had some problems, things I would normally expect to see on glassdoor. Because of the way they encouraged it, glassdoor was flooded with 5 star reviews that made it impossible to find any negative ones.
I no longer even check Glass door.