How interested would users be in a $0.10/message Twitter clone with (however many nines) guaranteed uptime? Twitter should limit the number of messages a regular user can send (over a given period, possibly) and charge a nominal premium fee or rate for the heaviest users. It's an obvious business model, and everybody wins (except for the heavy users who expect the service to be free of charge, who are thus kinda cheap).
That's a bad alignment to have if you want to make money. You especially want your biggest users to win. ISP bandwidth caps are a textbook example of how ISPs are struggling with this issue as we speak.
Right but downloading a DVD is definitely more demanding on any network than routing text messages and micro-blog posts. The revenue would make the product far more compelling for every-day use because there would be a guarantee of reliability, funded by subscription fees or rates. But infrequent users could use it for free (cap free messaging), and see ads.
