BrandZ, which bills itself as the world's largest brand equity database, annually crunches data collected from more than 650,000 consumers and professionals in 31 countries. Its annual comparison of 23,000 brands developed with MillwardBrown -- an agency specializing in advertising, marketing and brand equity research -- put Apple atop its 2011 list. Unique with the list is that it focuses on brand names -- which can be a single product or product line -- rather than companies as a whole (although some companies keep all their offerings under a specific umbrella). Apple ( AAPL), according to its research, was the world's most valuable brand, increasing its "brand value" by 84%, to $153 billion. For 2011, it replaced Google ( GOOG), which held the top spot for four years and was well ahead of Facebook, despite that company's 246% "surge in brand value." BrandZ credits successful iterations of Apple's product line -- the iPhone and iPad -- and "anticipation of a broadened strategy making the brand a trifecta of cloud computing, software and innovative, well-designed devices." Stressing the importance of perceived value, Sullivan points out that Apple has "clung to its pricing model" in good times and bad. Although some products occasionally drop in price slightly -- such as the latest, entry-level iTouch -- Apple chooses to keep a level pricing strategy even as its technology evolves. "They also have built in obsolescence," Sullivan says. "That's another big one of their marketing strategies. By building in obsolescence and continuing to innovate, they are giving people reasons to continue to buy their products."