NEW YORK (AdAge.com) -- Attention brands: Twitter users aren't talking to you or about you. In fact, they barely know you exist.

That's one of the conclusions of a six-month analysis of the service's ubiquitous 140-character messages conducted by digital agency 360i and released today.

Despite marketers' embrace of the medium, brands are finding themselves on the outside of the conversation. Of the 90% of Twitter messages sent by real people -- the other 10% come from businesses -- only 12% ever mention a brand, and most of those mentions are of Twitter itself.

Further, only 1% of consumer tweets that mention a brand are part of an active conversation with that brand, meaning marketers are, for the most part, conducting one-way conversations -- the opposite of the way consumers often use Twitter.

The most mentioned brands on Twitter tend to be there because they are part of a constant daily conversation, not because of anything the brand is or isn't doing on Twitter. The most mentioned brands on Twitter are, in descending order, Twitter, Apple, Google, YouTube, Microsoft, Blackberry, Amazon, Facebook, Snuggie, eBay and Starbucks.

Embedded in the culture
Snuggie is the surprise brand on the list, but that appears to reflect the brand's place in the culture, not its own Twitter activity. Official Snuggie profile @OriginalSnuggie has just 591 followers and @WeezerSnuggie, an account set up to promote the once-popular Weezer video, has just 693 followers and has been dormant since November.

After spending six months going over a statistically significant sample of 1,800 tweets, 360i Senior-VP Sarah Hofstetter was struck at just how mundane and personal they were. "They're mostly doing what people mocked Twitter about in the first place, as in, what I had for lunch."

The vast majority of real people's tweets, 94%, are personal in nature. Most tweets, 85%, are original and not re-tweets of other messages. They're also very often conversational: 43% of tweets begin with an "@" sign, meaning they're directed at another user, not the sender's followers at large.

While marketers such as Dell, Comcast, Ford and Starbucks have been, at times, clever participants on Twitter, the majority of marketers use it as a mini press-release service. Only 12% of messages from marketers are directed at individual Twitter users, meaning marketers still see it as a broadcast medium rather than a conversational one.

Showing up isn't enough
"There is still a misperception that if brands show up, people will listen to them, kind of like Facebook a few years ago," Ms. Hofstetter said. "Twitter can be used as a promotional RSS feed, but that's not going to establish a relationship with anybody."

The study was conducted before Twitter took any advertising, from October 2009 through March 2010. Twitter has since rolled out a series of ad units including promoted tweets and trends. Ms. Hofstetter said the ads are great to help boost things already popular on Twitter. "They are only going to work if they are relevant in the first place," she said.

Twitter posts are intrinsically navel-gazing, conversational and personal, but they aren't predominantly self-promotional. Depending on your circle of connections, it can certainly feel, as Wired's Evan Ratliff noted, that "self-aggrandizement" is "standard fare" on Twitter. But the 360i study found only 2% of tweets were professional updates or career-related.

What do Twitter users talk about? Beyond the 43% of individuals' tweets that are conversational, 24% are status updates, 12% are links to news or comment on current events, and 3% are seeking or giving advice.

The good news for brands is that when a consumer does mention them on Twitter, they're usually not complaining about it. Only 7% of tweets mentioning brands indicated negative sentiment, 11% positive and an overwhelmingly 82% neutral.