Content marketing on social media depends on trends in consumer behaviors. A changing focus and emphasis on audience activities on social media are a key optimization problem in social media marketing (SMM). A solution to this problem lies in a field of ongoing empirical studies of posting frequency. In the review of the literature, authors highlight the role of social media as a promising channel for a direct interaction of companies/brands with consumers. Based on theoretical generalizations, authors present a generation sequence of an SMM content strategy. The article also includes an analysis of posting activities of users from Russia on well-known social media. A cost-benefit analysis of posting activities rests upon some factors: Socio-demographic characteristics of users, a content format, time and day of the week parameters, etc. Data come from such sources as aggregated statistics of social media and selective interviewing. An analysis of activities for users from Russia has shown that VKontakte is the most popular platform; Instagram is the second, while Facebook is the third. Odnoklassniki and Twitter are less preferred. VKontakte users respond best to short posts. On Facebook, entries with medium-sized texts have got the highest number of responds. On Instagram, long posts work better. The photo format is a leader in all of the social media. The video format has a middle position, while a text is the most inefficient type of content. There is strong differentiation in response time depending on a target audience. Findings have made it possible to present recommendations for optimization of content marketing.