Coupon.

Filthy day today, bucketed down with rain all morning.  So I've had wet socks and shoes all day.

On the way home I stopped for petrol.

'Would you like a receipt?', the attendant asked.

Now normally I say no, but for some reason I said yes.  She gave me the receipt, which had two buy 1 get one free offers on it and this other coupon with $10 off my next shop if I spend a$100.

I'll obviously have to say yes more often!!