What are marketing and purchasing departments doing with all the information about people's last-choice products?

Those orphaned products still left on the shelves when everything else has been cleared out—the clear, unmistakable rejects—are providing a huge amount of information about consumer products and consumer behavior if anybody is paying attention.

Who is gathering this information, what are they learning, and how are they going to use it?

If your answer is based on actual knowledge and experience in the field, please mention that.