Stores prosper when customers give them a high share of their spending (share loyalty) and retain them over long periods (retention). We investigate share loyalty by measuring the percentage of the customer's spending in their first store. Retention is measured as first-store retention over a period of 21 months. We study the association between these two forms of loyalty both directly and, by examining their correlates, indirectly. We find that first-store loyalty and retention are positively related but have only two correlates, brand loyalty and attitude to the store, in common. Several factors are correlated with only one form of loyalty. Store retention is particularly related to the accessibility of the store; approximately half of the reasons given for defection are related to store access. Specific age-income segments may have high first-store loyalty but low retention and practitioners can use this evidence in their choice of target segments. Store loyalty is explained as the outcome of several customer processes: as a 'time-saver' effect – a rational allocation of effort given available time and money, control by the environment, attitude to the store and a propensity for routine. The first was not well supported; there was evidence in favour of the last three.