Yes, it's pretty much a personal decision... I look at it in two ways:
1) To minimize the possibility that watching an image might trigger our minds to want to get a massage or hire someone. (no body contact)
2) Or, as a distraction and a way to take care of business at home so that I don't feel urges to have direct contact with a service provider.
There may be more reasons that each individual will consider, I would think...