Introduction: Altmetrics is an area under construction, with a potential to study the impacts of academic products from social media data. It is believed that altmetrics can capture social and academic impacts, going beyond measures obtained using bibliometric and scientometric indicators. This research aimed to analyse aspects, characteristics and potentialities for the measuring of the social impact provided by altmetrics in social media. Method: 100 papers with higher altmetric scores were gathered from SciELO's database using the altmetric.com tool. Analysis: Profiles from individuals on Facebook and Twitter acting or reacting to the papers were analysed. These profiles were categorized as Social Impact and Academic Impact. Results: The results strongly indicate the impact measured using altmetrics greatly reproduces the scientist-to-scientist relation, as do bibliometrics and scientometrics. Conclusion: The social impact measured by actions and interactions on Facebook and Twitter reach a significant 36%, attesting the potentiality of altmetrics for measurement, in addition to the academic impact and the impact of scientific results in society.