What needs to be done to make online advertising effective and profitable? First of all, you need to collect data in order to analyze it and build a promotion strategy. But simply installing Yandex. Metrica and Google Analytics counters is not enough. You also need to set them up correctly. There are typical mistakes that lead to incorrect statistics collection.
On many sites, the counter code is placed several times. And if the code is repeated three times, then artificial cheating occurs. Also, from the analysis, you need to exclude visits to the site by employees of the company to which it belongs, as well as programmers, SEO optimizers, etc., who work with it. After all, they perform different actions on the resource than a regular user. Therefore, a filter for such visits by IP address is needed.

If there are subdomains, the user first gets to the main site, and then to the subdomain. Therefore, according to statistics, it turns out that the source that brought him is not the key request, but the main site. This can also be fixed with proper setup.
When analyzing traffic, there are ways to distinguish regular site visitors from potential buyers. The latter perform the following actions on the site:
- go to the "Contacts", “Delivery"” page;
- download price lists;
- place an order online;
- fill out the feedback form;
- subscribe to e-mail newsletters.
The E-commerce module allows you to calculate the profit brought by site visitors. It helps to calculate the percentage of people who came for a particular request, and the amount of money they spent on online orders.

You also need to link AdWords with Google Analytics. For other advertising services (Yandex Direct, advertising in price aggregators, teaser, social, banner networks), the URL builder is used. URL Builder will help you understand what queries, from what source, through what specific banners, ads, queries a person came to the site.
To improve the efficiency of the site, relevant pages are needed. A person who wants to buy a camera of a specific model should get to the page with it by a query, ad or banner, and not to the catalog menu or the main page.
Only taking all this into account can you evaluate the conversion and the effectiveness of advertising on the Internet.