1. Introduction
Whether marketers understand how customers make their purchase decision is a very important issue for a company. It can bring numerous influences to companies for establishing an appropriate marketing strategy. Therefore, the research of each stage of buyer decision process is relevant for all the marketers. Teo and Yeong (2003) point out that the setting up of buyer decision process model can help managers to understand and forecast consumer behaviours, and thereby they can make effective decision for providing more acceptable offers to customers. Kotler, Brown, Burton, Deans and Armstrong (2010) also hold the same view and state that there are five main steps of buyer decision process, as outlined in Figure 7.8. Firstly,
223). Gough and Nurullah (2009) agree with this view and remind that the opinion of salesperson, consumers’ family, friends and the emotion, mood of consumers and the situation the consumers face to will affect consumers’ purchase decision. For example, sellers may use persuasive language to attract consumers to purchase their products and consumers may purchase a product by persuasion of their friends. In addition, Teo and Yeong (2003) mention that determining the advantages and costs of each purchase decision are fulfilled by consumers. They also define that “Benefits can be functional, operational in terms of durability and reliability or personal. Costs include both financial and non-financial aspects such as time and effort” (p. 360).

2.5 Post-purchase behaviour
Finally, the last stage of the buyer decision process is post-purchase behaviour which depends on the confidence and satisfaction with a purchase decision that consumers have made (Kotler et al, 2010, p. 224). Frambach, Roest and Krishnan (2007) state that further action after purchase can be encouraged by positive experiences with saving of time, financial expenditure, and improvement of knowledge. Moreover, when consumers can be satisfied by the previous experience with the purchase decision, there is more opportunity that consumers will make the same purchase decision in future, and the word-of-mouth communication also can bring a strong positive influence on