Sony's Blu-ray format offers improved picture and sound quality over DVD, but that alone wasn't enough to guarantee success. Sony fought tooth and nail to become the dominant high-definition DVD format, finally beating out HD DVD five years after its 2003 debut -- the HD DVD format pulled the plug on its operations just before the 2008 CES.
Blu-ray still hasn't overtaken the DVD, but it has been popular enough to be considered a hit.
