T-Mobile is boosting its prepaid offerings. Mike Katz, T-Mobile's president of marketing, innovation and experience, tells CNET that adding Mint and Ultra to its stable of brands "allows us to have more products and more variety to more customers, and have a kind of a proposition that works for everybody no matter what they're looking for. " He also said the company has been working to add value to its offerings by including more data or international calling at the same prices, not taking things away or raising rates