SMS cost a concern in FB buying Twitter

imagine FB did buy Twitter and really dig into their mobile strategy. How cool would that be.

Here's one reason it probably would not happen:
"Twitter pays for users' messages to be sent to cellphones. If Facebook were to offer the service to its 120 million members, that could be quite an SMS bill for the social net to deal with" (Source)

We need a new mobile alert solution. SMS is not it.