Apple has filed a patent for determining the popularity of a source of serial (sequentially released) online content based upon a number of subscriptions to the source. In other words, the patent calls for a method that would allow Apple to track how popular a stream of content, from the iTunes Store for instance, is based on how many users currently subscribe to it. The method seeks to create a new counting mechanism, as current techniques for analyzing the popularity of content take into account only the number of times the content item has been selected, purchased, and/or downloaded by a user. However, some sources of online content, such as web feeds and podcasts, include multiple parts, each of which may be available at different points in time. As such, Apple seeks to determine an item's popularity -- as a third-party -- without having access to information concerning whether and/or which specific items of content associated with the source of online content have been downloaded. The obtained information could be used to recommend other sources of serial online content to the user for consideration.