Our Marketing dep't wants me to do "usability testing" at an upcoming user conference -- a gathering of our software users. The conference's purpose: for users to improve their software skills and to learn about upcoming product advancements.
I proposed a card sort, because it's low-tech, relatively quick, and needs little setup. This meets y needs (I have something I need sorted), but does not meet the conference goals; it won't help users improve their skills or learn about upcoming product advancements. So it got lots of thumbs down.