Online marketers love Facebook's brand-marketing potential, but few have attempted to evaluate the site's value with as much depth as Fathom Analytics. This research firm compiled a wealth of Facebook-based data, both number- and sentiment-driven, on many of the world's biggest companies. You might be interested to see who tops their list, and why. Remember, happy customers are loyal customers, and some companies get lots more love than others.

Method to the madness
Ranking the best companies relies heavily on measuring "likes" and posts to their pages, as well as how quickly both metrics grow. Fathom also evaluates the more nebulous concepts of emotional response and conversational variety to arrive at a comprehensive 100-point rating scale. The emotional gauge is based on a semantic analysis system originally developed for the Department of Homeland Security -- it's not just a poor intern scrolling through thousands of comments and pressing a button every time the word "awesome" comes up.

A brand can be miles ahead on likes and yet lose out to others with better social engagement. YouTube and MTV, for example, are separated by only two points, despite YouTube's nearly 20 million lead in likes. MTV narrows the gap considerably with a much higher fan response -- they have nearly twice YouTube's posts despite the smaller fanbase.

The fab five
There's no sense investing in a company just because it might be big on Facebook. However, an engaged customer base is one of the best forms of advertising, and can be one way to gauge a company's staying power. Here are the five most socially engaged public companies (not subsidiaries) on Fathom's list:

Company

Likes

Emotion Score

Total Score

Coca-Cola (NYSE: KO) 36.6 million 61 89
Disney (NYSE: DIS) 29.8 million 57 88
Starbucks (Nasdaq: SBUX) 26.6 million 49 88
Wal-Mart (NYSE: WMT) 11.1 million 55 86
McDonald's (NYSE: MCD) 12.3 million 50 84

Source: Fathom Analytics.

The real thing
Coca-Cola's at the forefront of social commerce, as fellow Fool Tamara Rutter pointed out last year. Their fan count shows it -- they're far ahead of privately held Red Bull in the drinks category, and best similarly beloved Starbucks by a wide margin in both likes and emotion score. There's no better confirmation of your brand's appeal than finding out that your fans frequently use the words "love" and "happiness" to describe it. Of course, "love" is one of the most often-used words by all top brands' fans, but none of them seem quite as happy as Coke's supporters.

Magic kingdom
Disney lost out to MTV for engagement, but like MTV parent Viacom, the Mouse House has many brands, including its theme parks and TV channels. ESPN has been getting far and away more commentary than the much more heavily followed YouTube fan page. Even Disneyland gets more love these days than Google's video depot. Disney's social push extends to gaming, which it's leveraged to create one of the top apps on the iOS App Store. Brand diversity hasn't diluted this company's broad appeal.

Gotta get my fix
Starbucks is far and away the most popular food-and-drink destination in the rankings, and that's undoubtedly due in part to its pseudo-default status as a meeting destination. I've had more meetings at Starbucks than I can remember, and I don't even drink coffee.

The company's emotion score takes a hit from the strong negative emotions that occasionally balance out its positive fan posts. I've heard that it takes 20 good reviews to balance one negative comment, and some of Starbucks' fans seem to really dislike the company's recent price hikes.

Low prices, high engagement
This came as a surprise to me. Some of Wal-Mart's previous (and rather pathetic) Facebook-side efforts have been thoroughly dissected, and the megaretailer's fan count lags far behind the top three. But the pride of Arkansas tops its category, and initiatives like My Local Wal-Mart and Shopycat help keep fans connected at the local level. The company's also resisting the post-holiday exodus currently sapping Macy's and Target's fan counts, a sign of more durable appeal.

Are you loving it?
It might have more stores than Starbucks, but McDonald's doesn't have quite the brand cachet of its coffee-roasting rival. In my eyes, McDonald's above-average placement on this list is a big success. Its momentum is much stronger than Starbucks' -- every day, more than twice as many people become fans of McDonald's as of Starbucks.

Marketing unobtrusively on Facebook is a difficult line to walk, and McDonald's is thus far doing a good job. One of its latest initiatives was a holiday partnership with Zynga, which put virtual Mickey D's in Cityville for the month of December. The company also recently highlighted its farm partners on its Facebook page, a nice way to humanize what some view as a massive, impersonal conveyor belt of cheap food.

Foolish final thoughts
These companies are all rock-solid, and their fabulous fan bases should reassure investors, but not every company needs a major public face to be a big success. If you're looking for the stability of a proven business model for your portfolio, The Motley Fool's got you covered with a new report on 11 great dividend-paying stocks. Wal-Mart is one of our choices, and you can find out the rest -- just click here to get your 100% free copy.