When you particularly enjoy a specific Member's music and are regularly reposting their work, you can add them to your Starred List by heading to their profile and selecting 'Star Member':

If you so choose, you can remove them from your Starred List whenever you like by clicking 'Unstar Member' on their profile. You can easily identify your starred members on the campaign lists and your incoming requests (your Starred Members campaigns will also appear here), as the star symbol beneath their name will be orange. You can also star / unstar a Member by clicking the star.