On Saturdays like today I volunteer for four hours at an Oxfam shop. It's a fun job--most of my fellow volunteers are foreigners as well--mostly students who want to practice their English or to get some shop experience in hopes of getting a paying job at some point. Anyhow, working there today got me thinking about the differences between UK charity shops and US thrift stores. While you could say that the two terms are cross-dialectal translations of one another (as wikipedia does), the different focuses of the names reveal differences in the establishments themselves and the cultural attitudes to them.
shop vs. store
Generally, BrE uses the noun shop where Americans would use store, but for me as an American, a shop sounds smaller than a store, and indeed size is a major difference between the average transatlantic thrifting (US informal) experiences. Most UK charity shops are smallish shops in the high street (UK; = US 'on the main shopping street, downtown'), while US thrift stores often have warehouse or supermarket proportions. Because of the smaller amount of floor space, some UK shops can afford to be very choosy about what they put out for display. Oxfam recently had a campaign to discourage donations of "not so good" goods.
thrift vs. charity
More differences in the social attitudes toward these shops are revealed in the descriptors thrift and charity. In the past few years, attitudes toward buying second-hand goods have changed in the US (hence the popularity of eBay), but when I was a kid, thrift stores were understood to be 'for' poor people to shop at. Hence they were in poorer (or in my town's case, industrial) areas. Nowadays you can find many thrift shops in strip malls, mixed in with retail shops appealing to all kinds of tastes. The prices are still pretty cheap, though I expect that the influx of middle class thrifters and the need to pay rent in more expensive parts of town may raise those prices in places.
Charity shops like Oxfam are clear that their main purpose is to raise money--not to provide cheap goods to the community (that's a nice side effect). Our shop is particularly expensive (as customers like to tell me), but we generally charge what we think we can get for an item. This means that anything that has possible value as a collectible is priced only a bit cheaper than it would be in an antique or other specialist shop. Secondhand books are £2 or £3 for most paperback novels (new ones in bookshops are £6 or £7), but there are also art books and antique books priced at around £20. (£1 = ~$1.90)
A broader cross-section of the UK (than the US) population seems to frequent charity shops--not everyone would buy their clothes there, but most readers enjoy checking out the books. Although there are real charity aficionados here, there is not, to my knowledge, any equivalent of the US verb to thrift.