Marketing psychology is all about understanding the thoughts and resulting behaviour; of people who buy things. 

The decision to buy goods or services, may be understood as a combination of an individual's personality interacting with characteristics of a product; in a particular situation.

To understand marketing psychology; you need to study the characteristics of potential buyers, the characteristics of alternative products or services; and the different situations where the potential buyers may come together with the possible products.

Knowing the customer is the starting point for success in sales.
 

• Consider who is most likely to buy; and put most of your marketing effort into that group of people.
• Consider who could buy. This group may be much harder to convince; and ultimately, may not buy anyway. 
• Consider demographics that would not buy. They may have no use for the product; may have no access to the service; or have inadequate financial resources to purchase.

• It may be a waste of resources to try and market something to the second and third group may be 
  
  

Making a successful sale is usually a matter of understanding and satisfying either the customers needs; and/or their wants.


Customer Needs
Customer needs are not as complicated as their wants. 
In order to satisfy a customer's needs it may only require communicating information about a product (or service), that demonstrates the value to them. If people are aware of a need they will be receptive to buy. If they are unaware of a need; it can be easier to raise awareness of a need, than develop a want where no real need exists.


Customer Wants
Whereas a need may be considered to be a consumer's desire for the benefit of a particular product or service, a want is the desire for a particular product or service which they don't really need but they would like. If someone is in the city and they are hungry then they need to purchase something to eat. If they choose a lobster dish and purchase a dessert then these purchases are wants because they could easily survive by eating something else. 

In order to satisfy what a customer wants it is necessary to understand their attitudes, preferences, and desires - as well as their financial variables. Understanding why a customer purchases a product is usually related to their wants rather than their needs. It is an altogether much trickier proposition. Wants are those things a customer wishes they could have. They may be broken down into public and private wants.

• Public wants - those desires that are shared by many people e.g. most people want quality drinking water, food, housing, clothing, entertainment, health care, etc. 
  
• Private wants - those desires that particular groups of people have e.g. a family may want a new car, a sporting club may want a new sports hall, a school may want a new playground, etc. 
  
  
  

The Buying Process

Consumers are often considered to go through five stages when purchasing a product:

• Raise Recognition of a Need (or Want) - the consumer acknowledges that they have a want or need. If there is a sufficient gulf between what they have and what they need and it is considered important enough, then the consumer will recognise that they have a problem and will be motivated to do something about it. Their desire to improve their situation is stimulated.
  
• Gather Information - the person seeks information about products which may satisfy their needs or wants. This may involve drawing on intrinsic knowledge e.g. past experiences, or it may involve consulting extrinsic sources of information such as the opinions of friends, literature, advertisements, websites, and so forth. Usually the information gathered is not complete before the consumer moves to the nest stage.
  
• Evaluate the alternatives - here the consumer compares the information they have gathered about the characteristics of the different products or services they have discovered. They may be more interested in prices, quality, or other factors. They might also be influenced by perceived risk, time, and finances. Generally, they will choose the product or service that has the characteristics that best meet their desires.
  
• Making the purchase - barring some form of intervention, the consumer will now most likely decide to make the purchase. At this stage, anything which makes the purchase smoother and easier such as clear labelling and signage, careful product positioning, and good customer service is likely to assist with the purchasing decision.
  
• Post-purchase behaviour - the person then assesses their purchase and decides if they are satisfied with it, whether they are unhappy with it. They may even experience buyer's remorse. The feelings the person has about the purchase will influence whether they return to buy the product again, and whether they tell others about it.  
  
  

Those working in marketing are interested in all aspects of this process because understanding what a consumer is thinking at each stage represents an opportunity to sway the consumer's purchasing behaviour. At the post-purchase stage marketers may seek to reduce any dissonance the purchaser has about the product by reinforcing the positive characteristics of the product or service.