Source: Gary Leff - View from the Wing
Companion tickets get a bad name because there are so many scam offers out there. Companies have offered free tickets as incentives for a long time, but work to keep their costs down by making the tickets unbookable.
As a result when there are really great offers that allow a companion to fly for security taxes, for no additional miles, or for a co-pay of a hundred bucks they can go under the radar. The best deals get ignored because it’s easy to assume they’re too good to be true.