Hi everyone, I nabbed the $20 per month iPad recently with the data share SIM. My bill is set to automatic deduction so I was very lucky to check it this morning. There we a number of $28 charges for each month in my contract adding up to $1328. When I rang Telstra (mildly curious but mostly furious that there was a hidden cost I didn't read) they thanked me for bringing this billing error to their attention. Turns out there is a system glitch and it seems to me Telstra require individual confirmation.
Anyway - check your bill to avoid a nasty surprise!