SMS::Send is intended to provide a driver-based single API for sending SMS and
MMS messages. The intent is to provide a single API against which to write the
code to send an SMS message.

At the same time, the intent is to remove the limits of some of the previous
attempts at this sort of API, like "must be free internet-based SMS services".

SMS::Send drivers are installed seperately, and might use the web, email or
physical SMS hardware. It could be a free or paid. The details shouldn't matter.

You should not have to care how it is actually sent, only that it has been sent
(although some drivers may not be able to provide certainty).