I don't know if you had the same thing in America, Jilly, but when the books were released here, many bookshops encouraged customers to turn up in Hogwarts colours when the books first went on sale. I attended two of these occasions, and they were great fun, with sales assistants walking round in wizard hats and people turning up with house scarves - lots and lots of Gryfindors and a sprinkling of rebellious Slytherins!