Maybe we should all cut our Sparks cards up and send them to the Chief Executive. I also agree it's crap. Although I did get 20% off bedding which I used.
I like th Boots one but find the monthly or whatever vouchers you get in a post a pain as I never remember to use them.
We find the Nectar one really good as we have the credit card and our house and pet insurance through them too so we get loads of points which we save through the year and basically eat for free in January. Their double up thingie they do is a faff though.
I don't often shop in Tesco so although I have a card I never use it. Hadn't realised you can convert to Avios though - will start that.