What type do they do? Was anything about that mentioned?
There are many kinds of massage and some learn and do more than 1 or 2 types.

There is the basic surface massage, and there is the deep tissue massage, somewhere between is probably where to start.. many kinds in between too..

A really good one will ask how you are doing and it more or less pressure is needed for you. They also should be able to tell by feel, where your spasms & tight muscles are..

Many massage videos on you tube to give you an idea of what to expect, even some for TOS and upper-body, neck etc..