The "data plan" is required for all Blackberry phones. The $29.99 is Blackberry Internet Service which is for personal email, web browser, and chat, it is "unlimited." You can email, browse, and chat as long as you want. The $45.00 is using your "work" email, and internet on your Blackberry phone. Text messages, mms, etc., are part of a different bundle, not to be confused with Blackberry data plan.