A new study of smartphone data usage through wireless carriers (not including data transfers using WiFi) shows some interesting trends. One is that data usage among iPhone users (dotted lines) is generally higher than among Android smartphone users (solid lines). Another is the drop-off in data usage last December. iPhone data usage seems to be quite volatile, with large shifts from one month to the next. Finally, that Android smartphone carrier data usage by Verizon subscribers is consistently the lowest.
The results are based on a sample of 1500 smartphone users with installed data tracking apps. For those who noticed that there's no dotted line for T-Mobile, the research firm noted that there were too few T-Mobile iPhone users in the sample to provide reliable measures.
Source - Average Android, iOS smartphone data use across Tier 1 wireless carriers, through December, FierceWireless