It’s something of a natural move; Pinterest is already typically used for saving interesting images and other visual content, and Instapaper does the same with a focus on written text. Pinterest has been trying to focus on more editorial content for a while now, having introduced article pins back in 2013.
The Instapaper acquisition helps build Pinterest as a service where you can save editorial content now to read it later, something particularly important as social media like Facebook and Twitter continue to grow as the main way people read their news.
For now, Instapaper will remain a separate app, but its team will contribute to Pinterest’s products, such as improving recommendations. We wouldn’t be surprised to see Instapaper’s note-taking features pop up on Pinterest over time, either.