Over-the-top video service Hulu has undergone a transformative year, adding ad-limited and ad-free subscription tiers, putting heavy investment into new content and exclusives, and focusing on building rather than selling, as it builds up to take on heavyweight Netflix and Amazon.com's video service. Its corporate parents -- NBCUniversal , Disney and Fox -- are happy with that approach for now, which is good, as Hulu loses more money in the buildup.