When consumers buy products there are external and internal factors that influence their buying decision. A need for a particular product could arise or the consumers might have been made aware of the existence of a product that they might have an immediate use for or might consider to buy it in due time when they are convinced that there is a need the product satisfies or if there is a problem the product will solve.
If what came first is the “need” to buy a product, the first step will be to analyse and convince oneself that the need is genuine. After surpassing that stage, the consumers independently will go out in search of information about the said product. It also depends on the kind of product to be purchased where if it is a high value brand such as a car, the amount of “information” to be gathered will be more than a product that consumers buy habitually on an ongoing basis such as food items or newspapers etc. that they are well aware of their need and had been buying them many times, which would mean they do not need much information about going out and buying them. 
Then what comes next is the consumers will have to evaluate among various products, and the more the product is a high end value brand the analysis and the comparison will be more involving and takes more time than, for example, when one goes out to buy a habitual item such as sugar, salt, bread etc. because any brand will do the job. If the brand picked is wrong on an occasion, it is possible to pick a different one that meets the requirement next time. But when the involved item is a high end value brand, consumers will always have to be careful and engage in “dissonance reducing”  buying behaviour, in such a way that they will make sure nothing goes wrong with their buying, because the next time they will be able to learn from their mistake might be years ahead in case of buying a car, for example, unless they want to take a drastic measure to return it or exchange it for another one that could cost them unnecessarily more. 
Here it might be helpful to look at factors that influence consumers’ buying behaviour and consumers take their cue from many sources. Friends, the culture someone belongs to, the media, a role model, family background, social status, all these factors and more could influence the buying habits of consumers or their likes and dislikes. The need comes first or it could be developed, because if we take buying a vehicle as an example it does not mean people cannot function normally without it, but it could facilitate what they are doing, maybe by enabling them to manage their time better. If what is involved is going from place to place, it could be accomplished by using other available means of transportation, but none of them might be at the level of having one’s own car. And the above mentioned factors could influence or avail them convincing reasons to commit on a high end value item such as a car that has many other requirements that go with it.
Mentioning Abraham Maslow’s hierarchy of need theory could also shade more light on consumer buying behaviour and the theory starts from the basic individual needs such as food, and once that is satisfied the next natural step is to search for a lasting security in a form a job or a source of stable income. Once that is attained the next stage is social needs where individuals need to belong somewhere. Whether they form their own family or join a certain group that will make them feel they belong somewhere it is a social need that should be tended. When they surpass that stage and are satisfied with the outcome there will still be more needs where they might want to be recognised for some of the things they are doing, and all along they are also creating new needs as consumers. This means the job of the various businesses is not going to be only feeding people or mass manufacturing most of the products they will need. There is going to be a lot of distinguishing to make and manufacturers get their cue from these factors and are out to satisfy them. 
Usually, a consumer base of such sophistication has various buying behaviours and among them are the “cognitive buying” that involves those who have to make a complicated decision while they buy, simply because what they buy is a high end value brand where there is no room to make much mistake. Then there is the habitual buying where consumers are used to doing them many times and they can go out and buy them on impulse and most of the time they do not go wrong, and even if they go wrong it will be corrected easily. While picking any food item if it is the right kind that the consumers approve of, it means the requirement is met, but if it just happened to be the wrong kind it is easy to be careful next time, which could be next day, and in such a case not much harm is done, where the purchased wrong item could even be thrown out.
There is also the “variety seeking” buying spree where consumers will continue to compare products and these products are not high end value items, in fact they are similar with products consumer buy habitually such as food items. They have many brands that are worth trying and even if they serve the same purpose, they have something different they offer that could satisfy the need of a particular consumer for as long as the product is in use. The other behaviour is “dissonance avoiding” (Sweeney, Soutar, Johnson, 1996) where making sure it is done right the first time is required and such items could be expensive. As a result, consumers do not buy them frequently and some examples to cite are diamond rings, cars, etc where the difference of using different kinds of the products is not highly traceable, except that there might be a brand loyalty or it is trendy to do so. (Kasper, 1988)
In today’s world there are many sellers as well as buyers and when the consumers develop the need they have to go out and buy certain products. Alternatively, even if they do not have an immediate need the various sellers will usually take a pre-emptive step of making consumers “aware” of what they are offering. Such steps could have various outcomes and they start by making consumers aware of what they have for sale and it is up to the consumers to evaluate if they have the need for the products or not. The idea behind the advertising is either to create such a need and make consumers buy or simply to create the awareness. When the need arises and it is time for the consumers to start comparing and evaluating, the advertised product will be among the products other manufacturers are advertising. Hence, what advertisers are creating is a brand awareness environment around consumers when they start out and a knowledge base that will stay with consumers until it is time to put it to use.
The next stage in the process of advertising after creating the awareness is the “consideration” stage where consumers will know the existence of the product and what it avails, how much it costs, who is behind it, where to find it etc. It is at this stage consumers would investigate if they have a need for the advertised product although they might not know if they would have a need for it in the future. The next stage that comes in is the “affirmation” stage where consumers know the existence of the product, had asked themselves if they have an immediate need for it or not and they might have been convinced that they will give it a try in the future, but in the meantime they might want to know more about the product, in case there are similar products that give equivalent or better value.
The “confirmation” stage is when consumers were able to see more of the advertisements, probably have talked about it with other consumers and are convinced that the product has a good value that is worth considering when the time is right, which could be immediately or when the need arises. Normally this is the stage almost all passive consumers stay in for a long time before they move to the next stage. What comes next is “action” and it does not matter when it takes place in the life of the consumers, but they will somehow be able to buy the product for the first time. At this stage it is possible to do a much deeper examination of the situation at hand by going back to the previous stages because there are also competing products that could be given consideration since they could avail similar values. After making the evaluation, if everything has come together and the need is there, then it is possible that the consumers could take action, which is buying the product.
After purchasing the product consumers need “reinforcement” in order to keep “cognitive dissonance” at bay and this is the role of the sellers. Purchasing the product will enable the consumers to make decisions about their fulfilment level of the product they bought. [Dholakia and Morwitz, 2002) And once that satisfaction is there it needs to be fortified by “reinforcement”, which would be in a form of more advertising so that a continuation of using the product will be there and depending on the product and how durable it is, advertisers aim to make their products part of the lifestyle of those who are using them. Here also what is important is innovation, which would mean to make consumers by the product repeatedly it needs implementing it on an ongoing basis.  And many products could be mentioned such as shaving gears, brand name clothes, food items, drinks, the list could go on where they will blend into people’s life style so that it will be easier for consumers to identify with them while using them. 
This will bring us back to the cognitive, habitual, and reinforcement aspect of consumer behaviour. And the cognitive buying aspect is at work most of the time and is absent only when consumers buy on impulse or when thy buy habitually, because their decision making to buy a product or a service will have to be affected by internal and external factors. The internal factors are more complicated since they are dependant on many factors that include their education level, the amount of money consumers generate, cultural back ground, their upbringing and their status in life and more. All these and more are what make up the thinking and decision making power of individuals. However, there are external factors such as advertising or what others are doing, in case of role models that could influence consumers’ decision making. At times who is doing what might also influences consumers if they are identifying to a certain group of people and what they do could affect their decision making process.  The cognitive buying behaviour will make a big difference when making decision to buy high end value items simply because such items cannot be thrown out if some mistake in the decision making process had been made. A TV set for example has so many days to go back and get a refund or where exchanging it is possible. (Soutar and Sweeney, 2003)
The habitual buying is mostly suitable for perishable goods such as foods and any other non-durable goods that have limited use, because if a different kind of cereal is picked and it was not up to par in its taste with previous products, it could be dropped next time, but if it is found to be up to par or better than previous experiences it is possible to make decision about continuing using it based on the finding.
Hence, the conclusion is the cognitive, the habitual and the reinforcement stages of consumers buying habits always go together and sellers will have to be aware of them and utilise them in full force. Those who are involved in advertising will also have to know which behaviour to cater to when they advertise because it is much easier to sell habitual goods than high end value goods even if all of them require to be sold through the mentioned advertising stages to be effective. Those who put these methods to work effectively will be getting the better share of the consumers’ spending, even if at times putting a product on the crowded shelf is enough. But since it is possible to tune people to make certain products part of their lifestyle, advertisers who do not focus on such methods among the other behavioural aspects could lose a lot of business and lose many repeat purchaser.  On the other hand, those who fail to recognise Maslow’s hierarchy need theory will fare poorly in targeting consumers’ needs.
Dholakia, U.M., Morwiz V.G., 2002. Customer Satisfaction Measurement. Journal of Consumer Research. 29(2)
Kasper, H, 1988. On problem Perception, Dissatisfaction and Brand loyalty. Journal of Economic Psychology.
Soutar, G., and Sweeney, J., 2003. Are There Cognitive Dissonance Segments?
Australian Journal of Management. 28 (3),
Sweeney, J., Soutar, G., and Johnson, L., 1996. Are Satisfaction and Dissonance the same construct? Journal of Consumer Satisfaction, Dissatisfaction and Complaining Behaviour. 9, 138-143.
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