The obvious alternative to polling for data is to dis- tribute that data, as it becomes available, to lists of subscribers. This approach may be adequate for small subscription lists (for example, e-mail lists), but it will not scale to accommodate the growing subscription de- mands of Web site syndication. Furthermore, while such an approach may reduce the overall bandwidth usage of RSS (by reducing unnecessary fetches), it does nothing to alleviate the per-update stress on network links close to the source. To address these problems, we look to peer-to- peer overlay networks, which offer a compelling plat- form for self-organizing subscription systems. Several overlay-based group communication systems, including Scribe [7], offer distributed management.
