X Factor is something noteworthy or special. It is a quality which is hard to describe, yet all of us would like to have it. Letter X has been a powerful weapon in marketing for decades. Words such as eXtra, eXclusive, eXpertise, eXcitement or eXperience have been popular jargon among marketing professionals. Marketers play with the symbolism of "X" to evoke curiosity or intrigue in their branding.