18. The method of claim 1 , wherein the user has obtained the authorization credential in exchange for purchase of the digital work to which an annotation pertains.
1. A computer-implemented method for providing an annotation of a digital work, comprising: under control of instructions that are executed by one or more computing devices: receiving multiple annotations from different authors for particular content in a digital work; storing the annotations in association with the digital work; providing a list of abbreviated versions of the annotations to a user desiring to access one or more of the annotations, wherein the list presents the annotations in an order determined by reference to a criterion; receiving an authorization credential from a user desiring to access one or more of the annotations; and if the authorization credential is valid, providing a full version of one or more of the annotations of the digital work to the user in context with regard to the digital work.