Airlines typically provide discounts of 5–10% off of lowest published fares for leisure groups of 10 or more, even if you are not traveling together. For association or company meetings, domestic zone-fare discounts range from 40% to 70% off full, unrestricted coach rates, and do not require a Saturday-night stay.
The ones that are selling unpublished fares are typically selling consolidator tickets, which are the result of a contract between an airline and a flight ticket wholesaler. This generally only applies to international tickets, in the USA, the greatest percentage of consolidator tickets are round trips to World.
