Loyalty could cost you when it comes to the supermarket shop; that's despite customer programmes designed to keep you coming back. A comparative shop by Consumer NZ has revealed some pretty lack lustre loyalty discounts, with some offers more expensive than other supermarkets everyday prices. Loyalty programmes give retailers access to your personal data and allow them to track your shopping patterns and history; supposedly in exchange for a better deal at the checkout. Gemma Rasmussen, the Head of research and advocacy at Consumer NZ speaks to Lisa Owen.