There IS a monthly fee of £3 - seems reasonable for all of the above.
I applied for the Sainsburys deal a few weeks ago but their paperwork was all over the place and not clear at all..........
Everything you need in one credit card for a monthly fee of £3
With the All in One Credit Card you’ll get:
0% on balance transfers for 41 months from date of account opening with no balance transfer fee
0% on purchases for 6 months from date of account opening
0.5% cashback on all of your purchases with no limits or caps
No foreign transaction fees on purchases made abroad in the local currency
Retailer Offers - get five welcome cashback offers ranging from 5% to 25% at a range of well-known major retailers once you switch on Retailer Offers via Online or Mobile Banking.