Abstract: User distributed advertisements (UDA ads) facilitates insertion of manually selected ads into a document that is to be distributed (e.g., transmitted, published, and/or posted) such that the document is to be made available to other users. For example, manually selected ads can be inserted into an email to be sent to another user, a blog to be posted for viewing by other users, a message to be sent to another user, a message board entry to be posted for viewing by other users, a document published and made available to other users, etc. Hence, UDA ads provide a scaleable advertising platform that achieves at least some of the benefits of manual targeting. Charges might be assessed to the advertiser, perhaps subject to one or more conditions being met. Rewards might be provided to the user that inserts and/or distributes the UDA ad, perhaps subject to one or more conditions being met. Performance metrics of UDA ads might be determined and used for various purposes, such as later ad serving arbitrations.