Facebook is working to combat a decline in people sharing original, personal content, the fuel that helps power the money machine at the heart of its social network, according to people familiar with the matter.

Overall sharing has remained "strong," according to Facebook. However, people have been less willing to post updates about their lives as their lists of friends grow, the people said.

Living it up during your 'sickie' today? Hot tip: don't do this. Credit:iStock

Instead, Facebook's 1.6 billion users are posting more news and information from other websites. As Facebook ages, users may have more than a decade's worth of acquaintances added as friends. People may not always feel comfortable checking into a local bar or sharing an anecdote from their lives, knowing these updates may not be relevant to all their connections.

According to one of the people familiar with the situation, Facebook employees working on the problem have a term for this decline in intimacy: "context collapse." Personal sharing has shifted to smaller audiences on Snapchat, Facebook's Instagram and other messaging services.