Aggregators are the most common use of feeds, and there are several types. Web aggregators make this view available in a Web page. Aggregators have also been integrated into e-mail clients, users’ desktops, or standalone, dedicated software.
Aggregators can offer a variety of special features, including combining several related feeds into a single view, hiding entries that the viewer has already seen, and categorizing feeds and entries.
Other uses of feeds include site tracking by search engines and other software; because the feed is machine-readable, the search software doesn’t have to figure out which parts of the site are important and which parts are just the navigation and presentation. You may also choose to allow people to republish your feeds on their Web sites, giving them the ability to represent your content as they require.