If you're thinking of going into a K-12 ed-tech company, the first thing you should know is this: School districts are BROKE. They do not have the money to pay even nominal fees for technology services and it doesn't matter what market you're in.
These arguments go all the way back to Thomas Edison. He promoted the phonograph and motion pictures as beneficial educational tools, not for baser entertainment pleasure. Many new media since then such as television and computers have been argued likewise.