Link: http://en.wikipedia.org/wiki/Molybdenum_disulfide

Molybdenum Disulfide is known for it's ability to keep a part lubricated and low wear protective properties under extreme pressure. With Anti-Seize Compounds there is a lot higher percentage of solids, Molybdenum Disulfide is a solid, as a percentage of the compound than grease. Solids cost more than the carrier, such a petroleum o synthetic but solids is what protects most your parts.