You can collect digital bonus stickers. Each flap you buy is saved in your account. Every sixth flap is free. In order to automatically receive a free flap you must have an account and shop logged in. Shopping as a guest will not save your flap purchases.
Old bonus-stickers stay valid. You can send them to us by regular mail and we will transfer them to your account. If you don't have an account yet you can easily create one in the upper right corner (My account -> Registration).