If I had twitter I would spend the day posting a link to this thread on the twitter feeds of every single retail chain I can think of. I can't stand being asked personal questions by checkout staff, especially when I know they had been told to do it my management in some misguided pursuance of 'improving customer experience'.
Dear managers of all retail chains: Shopping is not a leisure activity, it is a chore just like doing the washing, or cooking dinner. We want to get it over and done with as soon as possible. It is never going to be an enjoyable experience.
Dear Sainsbury's Managers: I don't want to be interrogated about how my day has been by your checkout staff. It has usually been shit but having to lie about it with a bland 'fine thanks' makes me uncomfortable. Your checkout staff don't want to know the real answers about my work stresses or family illnesses either.
Dear Bank Head Honchos:Asking customers what they plan to do with the money is intrusive and rude. Not everyone spends their entire lives taking money out of the bank to go off on lovely shopping sprees. What about the people who are withdrawing money to pay for funerals, or replace or repair things that have broken yet again and will struggle to eat that week because they've had to buy a new washing machine or whatever. They don't want a nice chat about it with the bank clerk.
Dear M&S/Next managers: The 'positive comment about your purchases' at the till is false and pointless. We know you've told them to say it.
I don't mind chat with the checkout staff, but it needs to be neutral and impersonal. We're British, so can talk about the weather for hours. This is especially good if the checkout staff can't see outside so keeping up with changes in the weather 'is it still raining outside?' would be fine for example.
Did you find everything you need? would also be a good one, and even better give them the facility to record the comments and send them off to someone who can act on them. One of many thing that annoys me about shopping is finding that what I wanted has run out, they don't have my size or things had been moved around so I can't find them.