"Thread Necromancy considered harmful" considered harmful

Many online message boards have rules against "thread necromancy," the posting of a new message to an older discussion, because it is considered harmful to the community to have an old discussion from the past brought back up again.
 
In some cases this is true:

• If the previous discussion was controversial and topical, reviving the discussion may only lead to renewed hostilities and drama
• Many discussions are topical, and have little value once the events are past (nobody wants to debate who will win the Superbowl/Election/Oscars after it's over)
• If the new post is a response to the original poster or one of the original participants, there's a good chance the people are not even around anymore, so the feedback is likely to be unseen
• A new post to an old discussion may generate a large number of notifications to users who are no longer interested in the subject, or even no longer members, possibly causing lots of email notices to bounce among other things
• Having old discussions reappear as new content may annoy readers of the forum

These reasons are legitimate, but are primarily focused on the forum from the somewhat selfish perspective of existing participants.

A public forum with no restrictions on membership will always be fighting the problems of new users who don't follow the rules. There's nothing anyone can do to stop this, people simply won't bother to read the rules, no matter how insistent you are. So rather than drive yourself crazy trying to enforce unenforceable rules on a random population, limit that population. Make the forum private. A private forum will have a more selective and limited membership, making rules enforcement practical.

Private forums have advantages, but unless the membership is huge they will not generate much advertising revenue, nor will they achieve search engine ranking.

This is why revisiting an old discussion can be helpful not only to the readers of the forum, but to the forum itself. Generally speaking, if you have any of these goals for your forum

• Attract new members
• Generate revenue from advertising
• Generate awareness of a product, service, or system
• Provide technical support or product help to end users

then it's counterproductive to prevent all responses to old threads. Very few people will find an answer to a question because they first found your public forum and then used its built-in search functionality. Almost always, people will visit your forum because they found a specific reference to a problem or question in a search engine (Google, Yahoo, Bing, etc) that brought them to your forum. In some cases, your forum's discussion may be one of the top search results for the subject. When that happens, you are getting traffic specifically because of that old discussion. Hundreds, maybe thousands of people are coming to your site hoping to find a solution based on your search engine ranking.

If you prevent any future updates to the discussion, you are actually hurting the user experience for search engine visitors. They see your site highly ranked, they visit, and they find that your sites information is out-of-date, or has no good answers. They leave, frustrated, and move on to another site that does allow new information to be added to old posts.

A commonly reported bug with a sound driver has a solution on your forum which has helped many people over the years, but after the release of Windows 10, suddenly a slightly different solution is required for the same problem. Your policies prohibit a user from adding a new response to the discussion pointing out the new solution.


Which is the more appropriate place to post the new solution to the same problem? In a new discussion that nobody currently knows exists, or in the existing, highly ranked discussion where many people will go?

Would you rather have visitors to your site consider it a helpful resource, or a waste of their time?

Make your site more valuable by allowing additional information to be added to old discussions. Enforce thread necromancy rules selectively per discussion, not with a blanket rule.