Do you use Glassdoor to evaluate prospective employers for culture, etc.? A report in the Wall Street Journal (paywalled, so no link) reports:

An analysis of millions of anonymous reviews posted on Glassdoor's site identified more than 400 companies with unusually large single-month increases in reviews. During the vast majority of these surges, the ratings were disproportionately positive compared with the surrounding months, the Journal's analysis shows.
Slashdot, “How Companies Secretly Boost Their Glassdoor Ratings”