An unusual promotion from Apple allows users to get up to $20 for free when they preload their account with up to $200. This promotion only runs from Dec. 17 to Dec. 20 in the U.S.
Once you add money to your account, it would be used for things like iTunes purchases, App Store purchases and iCloud Storage. However, it cannot be used to purchase gift cards or get cash back. Adding Apple ID funds could be a good way to deal with avoiding small monthly charges to your credit card for iCloud or Apple Music, and the 10% bonus adds even more incentive. Apple has a step-by-step guide.