14. The system of claim 12 , wherein the identified customization is not one of the at least one customization in the customization database.
12. An end-user system comprising: a plurality of user devices, wherein each of the plurality of user devices is configured to display a document to a user; a local data server comprising a plurality of databases, wherein the plurality of databases comprise: a post database, wherein the post database contains the content that is displayed to a user via at least one of the user devices; and a customization database, wherein the customization database comprises at least one customization including a customization file comprising at least one page fragment for insertion into the document and a metadata file; and an end-user server configured to: retrieve a document comprising digital content via a communication network; identify the presence of at least one insertion point within the document, wherein identifying the presence of the at least one insertion point within the document comprises: receiving data identifying one or several indicators of an insertion point; and searching the document via a search engine for indicators of an insertion point; identify a customization comprising a customization file comprising at least one page fragment for insertion into the document and a metadata file from the customization database, wherein the customization has a customization name; parse the customization name; determine a customization location, wherein determining the customization location comprises: identifying a designated insertion point for receiving the customization; and identifying a destination location in displayed digital content for the customization, wherein the destination location is the location at which the customization appears to a user accessing the document, and wherein the destination location is not at the insertion point; insert the customization into the document at the insertion point; and output the document including the inserted customization to at least one of the user devices.