Is Pinterest social media?
Social media is a phenomenon so large as to have a myriad different definitions. Therefore, answering a question whether anything is considered a social media platform will depend on the definition you're using.
In case of Pinterest, however, there's a debate whether it can be considered a social media platform. The reason for that is Pinterest does not really focus on building communities or user interaction — for example, there's no Like button. Instead, it's main objective is to be a self-service image search and discovery tool. As such, Pinterest is mainly used for finding inspiration or planning things like renovations, parties, and the like.
In summary, it is debatable if Pinterest can be considered a social media platform. While you can build an argument for it being a proper social media platform, it's way easier to build an argument against that seeing as Pinterest has no conventional social features like communities, user interaction, follows, or likes.