In the evaluation steps the consumer forms preferences among the brands. The consumer may also forms a purchase intention to buy the most preferred brand. But actual purchase decision is influenced by (a) attitudes of other and (b) unanticipated situational factors.

The extent to which another person’s attitude reduces one’s preferred alternative depends upon two thins (i) the intensity of the other person’s negative attitude towards the consumer’s preferred alternative and (ii) the consumer’s motivation to comply with the other person’s wishes.

Purchase intention is also influenced by unanticipated situational factors. A Consumer’s decision to modify, postpone or avoid a purchase decision is heavily influenced by perceived risk varies with the amount of money at stake, the amount of attribute uncertainty and the amount of consumer self confidence.

A consumer who decides to execute a purchase intention will be making up to five purchase sub decisions: (a) brand decision (b) vendor decision (dealer) (c) quality decision (d) timing decision and (e) payment method decision.