TMW runs the site, and it pays its employees according to whatever system of salaries and commissions and bonuses that are mutually acceptable to it and its employees.
There are a small number of TWM employees who work directly on the provision of services to the community of MATLAB users as part of their job -- Helen, Lindsay, Randy, and Ned. Those people may post semi-officially because doing so is their direct responsibility.
As far as I have ever heard, the rest of TMW employees post unofficially, as users (or, occasionally, as managers wanting to be sure that a difficulty has been addressed), and I am not aware that they receive any specific payment for doing so. Whether they post "during working hours" is, as far as I am concerned, entirely a matter between they and their managemen.
I would say, though, that IMHO, a company that discouraged its employees from occasionally helping to improve customer satisfaction would tend not to be a company of happy employees.
Best Answer