Bacn (pronounced like bacon), is email that has been subscribed to and is therefore not unsolicited (like email spam is), but is often not read by the recipient for a long period of time, if at all. Bacn has been described as "email you want but not right now."
Bacn differs from spam in that the recipient has signed up to receive it. Bacn is also not necessarily sent in bulk. Some examples of common bacn messages are news alerts, periodic messages from e-merchants from whom one has made previous purchases, messages from social networking sites, and wiki watch lists.
The name bacn is meant to convey the idea that such email is "better than spam, but not as good as a personal email". It was originally coined in August 2007 at PodCamp Pittsburgh 2, and since then has been used amongst the blogging community.
The word has also attracted attention in the professional email marketing community. Commentators have welcomed the distinction from spam and used the term to focus businesses on the need to improve the quality and value (to the recipient) of these kinds of transactional messages. A March 2011 diagram from Unsubscribe.com claims that over 27 billion bacn emails were sent every day in 2010.