Many executives of large companies are of the opinion that they have done all of their staff a large favor by hiring them in the first place.
This is more common in small and medium size firms, as large firms often get forced into corporate policies on such things.
At a place that I once worked for, the company electrician was expected to support the owners house and other businesses.
When the owner needed PCs for home or the other businesses, he would have a PC taken from the cube of any staffer who he felt did not need one.
The maintenence staff was sent out to the owners house whenever he needed the driveway cleared of snow, or furniture moved.
Bottom line, at many small firms, what the boss wants, he expects.
If you don'taccept tasks that are above and beyond the call of duty, you often will not move up within the company.
The trick is being able to 'read' the requests, and know where you can draw your personal line.
Chas