A retention rate measures how long a news server holds articles from a given newsgroup.

News Servers do not have unlimited storage, and due to this fact they can only hold posts for a short length of time before they must delete them in order to make room for new posts. This is a particular problem to binary newsgroups which transmit large volumes of articles.

For news servers provided by Internet Service Providers as part of a user's subscription package, typical retention rates are usually only 2-4 days. For premium news servers, this often rises to 1-2 months.

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