Retail chains are an economic system that sells consumer products to the end customer, i.e. a resident of a certain country, for which the customer pays them, and thus the chains make a profit. They are important for the normal functioning of the entire national economy of a country. Throughout history, market procedures and regulations have changed. The most important processes for the successful operation of a commercial chain with concentration are the introduction of privatization (conversion of national companies into private ones) and internationalization (stimulation of business with foreign countries). The leading retail chains in Croatia analyzed in this paper are Konzum, Kaufland, Lidl, Plodine and Spar. Analysis of market shares is one of the most important items for the better performance of a retail chain and its survival on the market. Market shares were estimated using Google Trends. Google Trends allows you to search for popularity and interest on the Internet search engine Google for a selected topic in a certain geographic location and time. A good marketing team is responsible for a successful business with profit. There are a large number of companies on the domestic and foreign markets that compete for survival by price and quality, and the company that retains the largest number of customers achieves a so-called competitive advantage. In addition to the already mentioned internationalization, the liberalization of the trade market is also important, which enables easier access to entrepreneurship, regulates the domestic market and competition on the same.