The social marketing paradigm has been changing due to the use of digital social networks. This causes Non-Governmental Development Organizations’ efforts to focus on achieving a greater reaction from the public in these communication channels. We propose that the way forward is to analyze aspects of messages that give rise to a greater response from the audience. In this regard, we have analyzed 3,608 Facebook and Twitter publications with the combination of content analysis and correlation analysis. We have considered three aspects: Purpose, theme and quality of the message. We have also listed a breakdown of quality and purpose parameters in order to become more fully acquainted with these aspects. The objectives of this research are firstly to carry out the communication profiles of the NGDOs studied from the points of view of the organizations and the public. Secondly, to analyze the reaction from the public (interactions) measured by the sum of likes plus the number of shares for each post, on Facebook and Twitter, according the parameters considered. The results showed that the most published messages from the organizations do not usually coincide with those that have the most impact on the public. Another proven aspect is that Twitter posts about behavior have more effectiveness than informative messages. Likewise, quality aspects, such as hashtags, mentions, or links, are not succeeding in generating public reaction.

Keywords: Social marketing, Digital social networks.