For the last two jobs I've taken, I looked at the Glassdoor salaries.
The first was right in the middle of the range Glassdoor stated. The second was actually much higher than what Glassdoor said, likely because I was joining a new team on a new project with a good budget.
Idk if it's being gamed. But if anything, I'd imagine it would be lower than what they would offer, simply because the data might be from employees that have started long ago and haven't gotten raises to match what a new offer would given for salary. As well as dated information (someone added their salary 3 years ago, but has gotten raises and hasn't updated their salary on Glassdoor).
Is that aspect being gamed as well and in what direction? advertising higher salary then what they would actually offer?