To answer your last question: because when I go abroad, my phone just works almost everywhere I go. Literally when the plane lands, I get a text message from T-Mobile saying "Welcome to _____" with additional information about my service in that country. Places like Mint, Visible, Ting, etc all charge you per text/minute/MB used abroad which makes them a non-starter since that's usually where I'm going to be using my phone even more than usual.