The Librarian in Black has a post about a service that provides time-released RSS which they call AutoResponder. The price seems a bit steep but it is centered towards business.

A number of potential uses are listed on the service's website, some of which might be useful for libraries: delivering a training course one chunk at a time, a series of photographs or historical documents, or a series of podcasts.

The idea has been around for awhile and the first major use I saw was the delivery of book chapters over time. One example is Cory Doctorow’s Someone comes to Town, Someone leaves Town.

...doesn't matter when you first subscribe, this feed will deliver the book to your feed reader in the right order, a couple of chapters a day, over the next month.

Feed Hoster is the hosting provider for the feed, who offers serialized options. Another interesting example is that of Light Cone which uses data from An Atlas of the Universe and gives you a personal rss feed about what stars and objects light has passed since your birth.

Chi Draconis is 26.3 light years from Earth. It was enveloped by your light cone 3 weeks ago.

FeedCycle provides serialized feeds for Project Gutenberg texts. They also provide a free plan which may be usable for some library experiments.

For the homegrown solution there are a few options which include using id’s and other options in the url string or using redirects and timestamps. The latter has some potential problems with aggregator support and shared aggregators.

Something to think about.