I would contact more schools to make arrangements for WyzAnt tutoring. I think that is a great market to get more students. School is not easy, and even serious students can struggle at times. I think this would give WyzAnt a step up on the competition.
Decrease the 25% commission tutors must pay
I would raise the pay to 85% per contractor (reduce overhead to 15%), and allow instructors to promote their own website more efficiently.
I would charge students and tutors less to use the services.
Provide an avenue for tutors to communicate with each other, in cases where a tutor needs assistance from another tutor in a particular topic. That would be my only suggestion.