This article is part of the interim results of a large scientific project «Study of the social impact of electronic interaction between citizens and authorities in Canton Petersburg on the example of urban digital services», conducted under the auspices of the Russian Science Foundation & St. Petersburg Science Foundation. The article aims to demonstrate one of the approaches for assessing the social impact of urban digital services through an analysis of meeting the digital needs of citizens. The theoretical framework that allows us to consider digital interactions as social communications, mutually beneficial for service providers and consumers, was the concept of social capital, that can occur in interactions when using digital services. Two social groups were selected as the objects for research of the digital needs of citizens: parents with children of preschool age and the disabled; as a digital service with elements of personalized service provision, the mini-application «I live here» was analyzed on the platform of VKontakte, which is part of the Ecosystem of urban services «Digital Petersburg». Conclusions were drawn on aspects that affect satisfaction with services, and the concept of social performance was clarified. The areas identified for measuring the social impact of digital services are defined, taking into account further analysis of the digital needs of the population.