By 1957 there were approximately 200 trading stamp companies in operation.[1] Typically, merchants would pay a third-party trading stamp company for the stamps, and would then advertise that they give trading stamps with purchases.[2] Large retailers were usually given a discount on the stamps while smaller retailers generally had to pay the full cost of adopting the trading stamp program.[5] The intent was to get customers to be loyal to the merchant, so that they would continue shopping there to obtain enough stamps to redeem for merchandise.[4][5] Customers would fill books with stamps, and take the books to a trading stamp company redemption center to exchange them for premiums.[6] Books could also be sent to the trading stamp company in exchange for premium merchandise via mail order catalogs.[6] An example of the value of trading stamps would be during the 1970s and 1980s where the typical rate issued by a merchant was one stamp for each 10¢ of merchandise purchased.