Friendly colleagues, good management, variety of writing jobs.
I'd say mutual respect and friendliness.
In contrast to other sites, there is a real "live" support service here. All issues are resolved promptly. My advice to pass a test: always use Grammarly to check your work (grammar and plagiarism) by yourself :)
They are a good company if you need some full-time but remote work or work only a few hours per week. I started here as a freelancer working about 6 hours only on weekends. But my official employer went bankrupt that's why I moved to Cool.Club as a full-time writer.