My last search of SPAM on the Internet resulted in more than 100,000 hits. Teachers and librarians are consumers too. They have limited time. They want information that can help them do their job better. I would guess probably not.
Testing is what direct marketing is all about.
Sure, find out what the response is. Find out how these prospects turn into customers. We're all for that. And, be very careful on the roll-out. Make absolutely sure you know what list you are using.