If it's any indication on the informedness of the article:

  In reality, an MMS is about one million times more data than a text message.

The payload of an SMS is 140 bytes. The MMS specification does not specify a limit, but providers often cap it at 300kb. Which, of course, is about 2000 times more.

Now, if an MMS had about a million times more data than a text message, that would make each message about 140 megabytes.