In this paper I will explain the notion of business marketing and name its basic concepts. After that I will describe the idea of Mystery shopping, which is the topic of this paper. Considering many consumers (including myself) have found themselves in an uncomfortable situation while shopping, due to a seller’s or service provider’s wrong approach, and have been put off buying some product, I have decided to explain the concept of a mystery shopping by presenting myself in the role of a mystery shopper. I will explain what my task is, who is sending me (where I am employed as a mystery shopper) and where to, how I will manage to collect all the important information whie acting as an ordinary customer without exposing my true identity, and what is important to find out as a mystery shopper working for a company (the methods I will use during the shopping). I will also describe the company hiring mystery shoppers and its demands. Many customers can be “too demanding”, sometimes they ask too many questions which after a while start to annoy the seller and make them become less polite and patient towards the customer. However, as a customer, I am always right and I want to make sure that I am buying the product that will satisfy my wishes and needs. As a customer, I am not always sure which product I need, or I cannot decide between two very similar products by different brands, because I do not know which one is of a better quality (for example, is “Suncokret” or “Dijamant” oil better), or I cannot find a certain product and similar. In all those situations I need a seller’s help. Sometimes customers can “get lost” looking for the seller. After finally finding him, in most cases the seller is not interested in helping, finds the customer annoying and does not understand why he is being asked questions the customer can answer by himself. In those cases it is important for me to document that kind of a behaviour and also see if the company is applying all the concepts of marketing and in what way: what is the process of purchase like and if there is lack of products (if so, it is important to find out why it happened and if the product will be restocked in time). It is also important to check the knowledge of the employees, how well they are doing their jobs and whether they meet their employer’s criteria. The process of mystery shopping is used in business marketing to improve marketing and companies’ management in order to increase profit, which is the result of customers’ satisfaction with the company. It is done to compare prices and quality of service between competition and similar.