With my iPad2, I got me a SIM-Card with a volume based plan, but I hardly ever used it because I am almost always near a Wifi-Connection
When I changed to the New iPad about a month ago, I reactivated the SIM and used it a bit, but not very much.

A few days later I checked the "Cellular Usage" in Settings and was shocked!
It showed 168 MB under Sent and a whopping 3,4 GB under Received.
The date of the last Reset was the day I inserted the SIM into the New iPad, but in all last year I would not have used this amount of data.

All I ever did was check mail when I was out and visiting a couple of Websites, no Downloads, no Videos etc.

Today I received the bill from my Carrier. I have 1 GB included in the plan, anything more would have gotten rather expensive.
But to my relief, It seems I actually stayed well under the 1 GB limit since I did not have to pay extra.

But the question remains, WHY would Cellular Usage show me such a high amount of traffic?
It did not change when I was using Wifi rather heavily, so it has to come from somewhere else.

Did this happen to anybody before?