BRANDS are basically a promise. They tell consumers what quality to expect from a product and show off its personality. Firms invest a lot on the image of their brands to foster sales and loyalty. But measuring their value is hard. Millward Brown, a market-research company, is one of several that takes a stab at it. It has just published its annual ranking of the world's "most powerful" brands based on consumers' perceptions and the performance of the companies that own them.
The top 100 are collectively worth $2.6 trillion, the firm reckons. Apple remains the world's most valuable brand, worth $185 billion, at the head of a trio of technology companies. None has increased much in value, however, since 2012 perhaps because they have been refining their products rather than being startlingly innovative. Microsoft, which tried to be startling by launching a radical new operating system, has seen its brand value fall. Apple's big rival, Samsung, jumped 25 places, partly by out-innovating Apple and partly by boosting its advertising expenditure by $1.6 billion.
Visa was one of the main brand sponsors for the 2012 Olympic games in London. But many of the big gainers profited from growth in emerging markets. That helps explain the jump in the value of beer brands like Brazil's Brahma, which is worth 61% more than last year. Tencent, an internet services portal, benefited from being innovative and Chinese. As sales slowed in Europe, Zara, a high-street fashion retailer launched online shopping for customers in China.
Luxury goods companies groom their brands even more carefully than most. Gucci, whose brand value increased by almost 50%, has invested in technology to support its online and mobile presence. The biggest riser this year, though, is Prada, whose brand value surged 63% as it boosted sales in both old markets and new. But even in Western Europe its most avid customers were Asian tourists.