Most of the them are probably only part time (i.e. 2-3 hours a day during peak hours and only 2-3 days a week) and they are probably counting the kitchen janito

Most of the them are probably only part time (i.e. 2-3 hours a day during peak hours and only 2-3 days a week) and they are probably counting the kitchen janitorial crew. 50 ends up just being a nice sweet marketing number (directed at both potential employees and for media hype).