Have you considered sponsorship deals with a phone company? I could see this being a way for phone companies to get their first customers:
"But, Mom, I have to get a phone now!"
"But, Mom, I have to get a phone now!"
It would seem we're into some kind of transition phase where digital education for K-12 will have to be completely furnished by school districts or this is another class divide. Many can't afford phones or laptops for their children. Where will the responsibility lie for this?
With that in mind it might be worth it to enable a feature that will allow teachers to also send an email to students who desire it, as to allow students who don't have phones to be included as they can access the internet at school (if they don't have the internet or a computer at home).
Laptops and tablets are already being used in certain school districts and required as such. Convincing the mobile phone providers that we only need IP access and not expensive monthly phone bills is going to be one ugly battle. Hence, my asking who's going to cover the subscription costs until this becomes settled and normal. And relying on someone like Google to make this "free" while becoming my child's identity provider is not OK.