Each time you repost a track you may be given the opportunity to follow another member in exchange for credits:

If you check the box, you will follow this member on SoundCloud and you will receive the number of credits shown.

Please note that if you decide to follow them, you must remain doing so for at least 14 days - if you unfollow within this time, the credits you received will be deducted from your account and you may no longer be able to earn credits in this way.