The development of the Internet led to a change in the business world. The use of computers and the Internet has developed e-marketing. E-marketing is the process of promotion, distribution, pricing on the electronic market, i.e. the realization of marketing activities using information - telecommunication technologies. One of the very successful marketing places of electronic markets are social networks. Social networks are a part of the Web 2.0 approach that represents the second generation of Internet services and the most developed communication in the virtual world. The main representatives of Web 2.0 technologies are: wikis, blogs, forums, social bookmarking and social networks. The first social network was launched in 1997 and was called Six Degrees. Today there are more than 200 social networks worldwide and the most popular ones are Facebook, Twitter, MySpace, YouTube and Pinterest. Social networks can be categorized according to different purposes which are business - professional social networks, networks for meeting new people on the basis of common interests, the social network for the exchange of information and media, and the like. All of these social networks are used as a good platform for marketing because the company can choose how it will introduce the product or service. In this way, users have an increasing insight into the brand, and thus closer to him. In addition, the company in a quick and easy way can find out user opinion about the brand, efficiently allocate marketing investments and the like. Today, the most popular social network is Facebook. In addition to meeting new people and finding old friends Facebook allows good marketing. Ads on Facebook may be in the form of banner ads, video ads, as a profile or created in other formats such as interesting games. Pinterest is a social network that is not as famous as Facebook, but has the fastest subscriber growth in history. The aim of Pinterest is to connect everyone in the world through content that is interesting with an image, a mission to help people discover what they like to do and encourage them to deal with in everyday life. Like Facebook, Pinterest is a good virtual place for advertising various products or services. Facebook’s marketing activities are much more prominent than Pinterest’s due to Facebook’s good name in the marketplace. While the advertising strategies of these two social networks differ, Facebook occupies first place for now since it is the most well-known social network.