The vouchers are valid through two years, which is considered long enough for customers not to feel coerced into spending the vouchers before they want to, but also short enough so that Tesco does not build up excessive financial exposure, as it is the case with many airlines, where millions of unredeemed flyer miles accumulate as a growing liability. Since Tesco tries to
stress the characteristics of a club, vouchers represent the club membership dividend (Humby/Hunt/Phillips 2003, p. 76).
Currently, about 14 million British shoppers receive a statement from Tesco every three months (this equals about 35 % of UK homes in every mailing).The annual nominal amount of vouchers redeemed by customers is about 200 million GBP which corresponds to a redemption rate of about 20 %. This is an extraordinarily high number, compared to the industry average of about 0.5 %. This success was achieved to a great extent through a detailed analysis of the data acquired via the Clubcard (Spethlift 2004, pp. 33-34).