Fruitcage, welcome to the party

It's great to have you on board (so to speak). Hopefully this will be the first of many postings!
I have only been asked for my credit card once, and that was in connection with an OpUp. I had the magic beep at the gate at LHR when flying to the US and was told that my seat had been changed / that I was now in Club World. However, the gate agent needed to scan my credit card before she could issue the new BP.
Apart from that one occasion I have never been asked.