Biggest problem with SMS is that it cost and its not cheap at high volumes. Twit...

		knodi on Aug 6, 2013 \| parent \| context \| favorite \| on: Twitter’s New Two-Factor Solution Kicks SMS to the... Biggest problem with SMS is that it cost and its not cheap at high volumes. Twitter pays a lot money to secure short-codes and delivery of SMS into countries around the world. Slowly they'll phase out the SMS auth and save money.