另一方面，还有工具理论。这表明，人类作为消费者，通过尝试和错误的方法进行学习，然后寻找一种能够产生增强效果的特定刺激(Durante et al.， 2016)。这是形成的，然后作为一种习惯的形式。这种理论是必要的，适用于客户行为环境中的各种一般情况。它进一步建议消费者通过尝试和犯错误的媒介来学习，在这种媒介中，某些购买行为会导致更有利的结果。通过这些理论，我们可以清楚地看到，营销的影响是以学习的形式呈现给顾客的。如果顾客受到激励，如果他们喜欢产品的质量，他们就会受到影响(Durante et al.， 2016)。有时，顾客甚至没有同样的需求，但他们仍然参与购买过程，因为他们知道其他人也在购买。
工具理论同样支持反应和刺激之间的联系。该理论进一步阐述了这样一种观点，即刺激产生的结果最令人满意的性质的参与者是习得的(Madzharov et al.， 2015)。例如，如果客户知道某个产品的价格降低了，但质量不变，那么客户就会考虑购买该产品。他会知道这个产品给他带来了巨大的价值。另一个例子是，当一个人通常在晚上9点听新闻，并且在看新闻的同时吃晚饭，那么晚上9点新闻的声音最终会让人感到饥饿。这甚至发生在它们不饿的时候，或者刚吃过东西的时候(Solomon, 2014)。
On the other hand there is the, instrumental theory. It suggests that human beings as customers indulge in learning through the method of trial and error, and then they engage in finding out a specific stimulus which can yield enhanced results (Durante et al., 2016). This is formed, then subsequently as a habitual form. Such a theory is essential and applicable to various general situations within the customer behaviour context. It further provides suggestion that customers learn through the medium of trying and committing mistake wherein certain behaviour of purchase results in an outcome of more favourable nature. Through such theories, it becomes evident that the influence of marketing comes forward in the form of learning for the customers. The customers get influenced if they are motivated and if they like the qualities within the product (Durante et al., 2016). At times, the customers are not even having the need for the same, but they still engage in the buying process as they learn that others are also buying it.
The instrumental theory likewise endorses the connection between the response and stimulus. This theory elaborates further the perspective that stimulus producing the result of most satisfying nature for participants is learned one (Madzharov et al., 2015). For example, if the customer learns that for a product, the pricing has been reduced, but the quality is same, then the customer will consider buying the product. He will learn that the product is offering him tremendous value. Also, another example is that when one generally listens to news at 9 pm time frame and also has dinner within the same time while viewing the news then the sound of 9 pm news eventually will start making the person hungry. This happens even when they actually are not hungry or even when they have just eaten (Solomon, 2014).