Twitter's mistake was to ever allow such thing being completely free in the first place.
Telco companies will charge fees if an entity (private or public) wants to send alerts over SMS to their customers/users. I can't see why Twitter had to be different other than "we must grow fast!" mentality of a startup hungry for MAU.
NYC Subway MTA has significant revenue (>5 bi/year). Sure they can pay Twitter if this is how MTA users want to be notified. Worse case scenario, they will add a $0.01 "Twitter-fee" into ticket prices.
Telco companies will charge fees if an entity (private or public) wants to send alerts over SMS to their customers/users. I can't see why Twitter had to be different other than "we must grow fast!" mentality of a startup hungry for MAU.
NYC Subway MTA has significant revenue (>5 bi/year). Sure they can pay Twitter if this is how MTA users want to be notified. Worse case scenario, they will add a $0.01 "Twitter-fee" into ticket prices.