Perhaps there should be a time limit on the related posts that appear in the right-hand column, say a year since the most recent reply.
On the Boston board, e.g., there was a new post about a Burmese Food Festival next week in Lowell. One of the related messages was from a food fair in 2008! The most recent reply was in 2011. Useless, particularly for an event. Even for a restaurant still in business, stale information can be misleading.