Here is some more great information from RIM during Mobile World Congress 2012! The slides below show that carrier billing accounts for 34% of paid apps, PayPal with 23% and credit cards hitting a wooping 43%.
At this time carrier billing is only available on 40 carriers in 34 countries. That makes carrier billing a 3rd of payments even though App World is available in 164 markets. Since BBM connected apps released in July of 2011 App World has a massed 568 BBM Connected apps that have been downloaded over 140 million times!