When you purchase multiple packs of objects or brushes from the Object or Brush Market at the same time, we apply credits to your account so you can redeem them in your own time, on whichever packs you’d like. They also allow you to purchase multiple packs at a significant discount. One credit generally equates to one pack, but "Make Your Own Objects" (which allows you to create infinite object libraries of your own making) takes 2 credits.