If this is switched on, the feed page will contain an extra button:

Any follow.it user (or even non-logged in users, if the feed owner allows) can propose messages which they consider to be worthy of being sent through the feed. 

After a message has been proposed, a notification gets sent to the feed owner who then quality checks & sends the message, or deletes it. 

When is this feature useful? 

This feature is especially useful if it’s important for the feed to stay up-to-date, and there is a possibility that the feed owner isn’t the first to hear about relevant news. By using the power of the community all followers get updated much quicker.