This principle is as follows: resources for display are selected by relevance to the text content of a user request. Then is, if the text resource contains the maximum number of matches with the request, a reference to this resource and will be the first among the displayed as search result. There are other, less important and more difficult to understanding of the workings of search engines. However, the principle of contextual relevancy is the absence to date of other significant resources, a priority. Service Yandex is a leading, if not leadership, service provider, along with other world-class services services of Internet search. Many users search for and find the resources they need through the service. Principles of content in the system Yandex generally similar to the universal principles of contextual advertising, but there are a few more characteristic of this system of signs that advertisers should also be taken into account.

The more diverse set of terms, the greater the chance of an exact hit, which probably will increase the rating of a link to the advertiser in the list of results displayed. In addition, should be considered accurate spelling of the term, although this accuracy, as shown below, can be quite unusual form. Set of terms that are used for contextual advertising in professional language called "keywords", "hand column" or just "keys" can be extended in various ways. One of them – the use of synonyms, and clarifying terms. For example, together with the term "home electronics" can be used the term "home audio equipment," or "sale electronics.