If you join our music club, you will receive four free CDs. Whether or not you decide to cancel your membership, these CDs are yours. If you choose to remain a member and purchase just 2 CDs at regular price, you can choose another three free CDs. After your first purchase at regular price, you will receive 10 points for every CD purchased. For each 30 points you collect, you can choose another free CD! If you want to earn even more free CDs, have your friends join, too. You will receive three more free CDs for each friend who joins using your name. The best part is that you get 3 free CDs every time you have another friend join our club, so join today and start collecting your favorite CDs.

What detail from the text encourages music club members to get their friends to join the club?