I use my card for my weekly food shop, the cashback I receive can then be put towards the next months shopping.
I use my card not just for everyday items but for my big purchases too. I needed a new SatNav as I am always on the road.
I used my cashback savings to get the wifes Christmas present (and earn even more cashback). Dont tell her though!
We are currently renovating our house and my card meant we could spend that little bit more on the garden as we were benefitting from the cashback saving.
My card is great for those unexpected emergencies. Our fridge broke and our card meant we could afford to get one straight away.