Pros
It's a great way to make money in your spare time; you can log on as a "floating tutor" any time you are available, and you will get paid at the regular rate for any students you tutor. Also you can schedule times if you know that you will be free, and you will get paid at a "half-rate" during that time, even if no students come your way. They are pretty careful to keep you busy with students if you have actually scheduled the time!
Cons
It seems like the tutors can get blamed for things that are the students' fault. The student can write a bad review for you, even if it's the fault of the classroom software, or if the student just wanted a free quick answer (which Tutor.com policy forbids us to give); and that will drag down your overall "student rating." If the student rating falls too far you can get in trouble, and the management doesn't seem to be able to distinguish between problems that are caused by lazy/abusive students, or by the classroom software. Also, you can get in trouble for staying in a session too long, even if the student has brought you a really involved and multi-step problem, and has no idea how to even start it.