What are the differences between mark as important, pinned posts and promoting a user's posts to top of News Feed on Workplace?

Marking a post as important highlights important content. Posts marked as important are shown at the top of News Feed for all group members.
Pinned posts are a way to ensure an informative post remains at the top of a group. As pinned posts are only shared to the top of a group, and remain indefinitely, the feature is often used to share details about the purpose of the group. Learn more here.
Promoting a user to the top of News Feed means everything that user posts will be surfaced to the top of the News Feed for every employee. This option is usually reserved for executives or other accounts that require significant reach. Learn more here.
Was this information helpful?