Measuring the value of a company's brand is a bit subjective, but the folks at Interbrand have been doing it for 15 years. Apple (AAPL -0.35%) once again came out on top as the world's most valuable brand and saw its worth soar 21% over last year's ranking.

Taking into account the financial performance of the branded product and service, the role the brand plays in influencing customer choice, and the strength the brand has to command a premium price or secure earnings for the company, Interbrand is able to assign a value and rank the brands accordingly.

The prestige of the Apple brand allowed it to stay ahead of Google (GOOG 9.96%), which reprised its role as the second most valuable global brand. Its value only grew 15% from the year ago period.

Yet there were a handful of other companies that, although ranking lower than Apple or Google, grew their brand values at even a faster pace. Let's take a look at the three fastest-growing brands in Interbrand's 15th Annual Best Global Brands report.

1. Amazon.com (AMZN 3.43%) -- Rank: No. 15; Increase in Brand Value: 25%.
The just-passed five-day holiday shopping extravaganza underscores why Amazon is seeing the value of its brand soar. Over the entire "Cyber Five" selling week, Amazon recorded a 23.8% increase in sales, better than eBay (EBAY 1.32%), which was up 20.5%, comparative shopping engines (down 1.2%), Google Shopping (up 5.8%), and generic searches (up 19.1%). All this while sales at bricks-and-mortar stores inched lower 0.5% over Thanksgiving and Black Friday.

Last year Amazon recorded 903 million hits to its website during the holidays, nearly four times more than second-place Wal-Mart (WMT -0.08%), which had a seemingly paltry 250 million visits. Revenues hit $74.5 billion in 2013, and are already at $85.2 billion over the last 12 months, while third quarter revenues surged 20% to $20.6 billion dollars and sales of retail products jumped 16% from the year ago period.

The holiday season isn't over yet. Expect Amazon to break more records, and see its brand value rise even higher next year. Interbrand says Amazon Prime will continue to play a key role in its higher value.

2. Audi-Rank -- No. 45; Increase in Brand Value: 27%.
Cars from Toyota, Mercedes-Benz, and BMW may rank higher on the list than does Bavarian automaker Audi, but none saw their brands increase in value the way the Volkswagen division did, making it the top-rising automotive brand in Interbrand's report.

The brand consultancy highlighted Audi's A7 self-driving car unveiled at the 2014 International Consumer Electronics Show in Las Vegas, its plans to introduce 17 new or revised models, and the production of its new electric car, the R8 sports car. Combined, these innovations will help Audi gain on rival BMW, whose own brand value increased only 7% this year.

3. Facebook (META 0.43%) -- Rank: No. 29; Increase in Brand Value: 86%.
Far and away the best performer in any category across any industry was social media titan Facebook. With the 86% increase in its brand value, the networking site leapfrogged over many other companies on the list and moved up the rankings from mid-tier 52 to 29th place.

Interbrand pointed to the particularly strong earnings report it record in the second quarter where revenue doubled from $562 million last year to $1.4 billion this year as its mobile phone ad business gained strength. Of course Facebook did warn that its revenues would "decline meaningfully" across the rest of 2014, but the 59% jump in revenues wasn't too shabby. Investors might not like the idea expenses will exceed revenue growth, but two-thirds of its revenues come from the mobile channel and that bodes well for the future.

Facebook has proved remarkably efficient at using the channel to accelerate revenue growth. Because advertising on mobile devices is different than on a desktop, the social networking site has had to adapt to the new medium. As Interbrand notes, after shelling out billions for the WhatsApp messaging service OculusVR, Facebook "is building a vast product portfolio, brimming with competing services and apps."