I'm currently in charge of memberships at my work, and I will say that in many ways I wish we didn't offer an educator-specific membership level. If you decide to go the educator-specific membership route, I'd be very clear in who you define as a teacher; is it only those who teach grades K-12? What about administration or support staff? What about people who consider themselves teachers, but who aren't classroom teachers? Honestly, if I were creating a program from scratch I wouldn't separate out a teacher-specific membership, but would instead concentrate the institution's energies on providing services of benefit to teachers and to schools (teacher training opportunities, field trips, programs you can bring into the classroom, etc.). You could always boost awareness and encourage teachers to become members by periodically providing teacher-specific events or sending special mailings or invitations to take advantage of special limited time teacher appreciation discounts. I'd much rather just get teachers as regular members than have them pulled out as a separate category of membership.