the purpose of pinning content to a pinterest board is to remember it. this makes the content far less ephemeral than feed-based social media channels such as twitter, linkedin and facebook. in fact, the lifespan of the average pin is a few thousand times greater than that of a facebook post.
pinterest is also a more e-commerce friendly channel than other social networks. more than 90% of pinners have used the channel to plan, research or make purchases. for b2c companies that sell physical products, pinterest is basically a second online store. for b2b marketers, pinterest has value as a way to visually promote content.
pinterest is also unique in that it is as much a search engine network as it is a social media platform. much like a google image search, the content is all visual, while keywords used in titles and board descriptions, pins and images help influence which content will populate the search results.