I cull my purse every few days but now don't accept vouchers in Smiths (wouldn't buy printer cartridges there anyway) and check through Sainsbury ones in store- last week they gave me one to say my shopping was 3pence cheaper than it would have been in Asda - pointless Asda is 15 miles away! the other thing is loyalty cards for coffee shops etc I have 5 different ones and one for my hairdressers which is probably the only one worth having - one free hairdo in every 9 so at £50+ a go its worth having.
To think that London, or anywhere else for that matter, does not belong to any one demographic