Where a mid-range smart-phone would consume about 100 megabytes of data a month, more advancedmodels like the Apple iPhone or Motorola Droid, with fully fledged browsers and access to thousands of downloadable applications, tend to consume over 500 megabytes a month.
But the follow on orders have been experiencing longer delays, and the more advancedmodels of the iPad Mini with mobile data support joining Wi-Fi, have had their release dates pushed back.