Do you know what Facebook is? How about Twitter? Of course you do - unless, as they say, you've been living under a rock. Nowadays, you'd be hard pressed to find someone who hasn't at least heard of these social media websites, even if they've never used them.

But what about HootSuite or RockMelt, have you heard of them? Or TweetDeck, does that ring a bell?

Now there are some social media names a lot fewer people may recognize. These companies don't get nearly as much press as Facebook, Twitter and other social media hotshots, but they're just as important in their own way. Without them, navigating and managing social media accounts would be a lot more difficult - maybe even impossible. Here are four companies that have been working behind the scenes to help make the social media industry the huge success it has become.

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HootSuite Media, Inc.
Vancouver, Canada-based HootSuite, founded in 2008, is a 48-person company that provides a social media dashboard for managing Twitter, Facebook, Linkedin and other social networks via the web, desktop and mobile platforms. The dashboard can also be used to publish messages and monitor conversations. HootSuite offers social media marketing services, too, such as an "Analytics" tab that aids in the analysis of followers by demographic data like location and gender.

Since August 2010, HootSuite has been operating under a "Freemium" business model that keeps the site free for 95% of its roughly 2 million users. Thus, the company only makes money from those who opt for its paid "Pro" or "Enterprise" plans - typically businesses with more advanced marketing and promotional needs. Although such businesses only make up 5% of HootSuite's user base, the company generated $1 million in revenue in the five months after the Freemium announcement. (For related reading, see Getting To Know Business Models.)

RockMelt, Inc.
Mountain View, Calif.-based RockMelt launched in November 2010, making it one of the newest Internet browsers. Key features include Facebook and Twitter updates and constant news feeds on the left and right edges of the browser window. Users can share web content with their social networks or chat with Facebook friends without having to open Facebook. Because RockMelt is built on Google Chrome, it can run any of Google's 3,700 Web Store applications.

RockMelt seems a good candidate for long-term success because of its relationships with Facebook and Twitter. The site already has several hundred thousand active users and over a million installs, though, like many new startups, it isn't yet profitable. "Over time, we'll make money through search, just like other browsers," said RockMelt CEO Eric Vishria in an article posted on on June 28. "And as we build in commerce and gaming features, that will bring in revenue as well," Vishria added.

British startup TweetDeck has been getting a lot of press related to the sale of the company to Twitter for an estimated $40-50 million on May 25. Twitter was keen on the acquisition because TweetDeck was the most popular Twitter application (other than Twitter itself) for posting status updates. Other TweetDeck abilities include sending and receiving Tweets and viewing profiles. Notably, TweetDeck is compatible with the Microsoft Windows, Mac OS X and Linux operating systems, and it runs on mobile devices such as the iPhone.

TweetDeck could help Twitter increase its dominance of the social media space because TweetDeck has made a number of improvements Twitter lacks, like the ability to post to multiple platforms in the same desktop window. The acquisition also prevents Twitter competitors from getting their hands on TweetDeck and using it to their advantage. (For related reading, see 5 Top CEOs On Twitter.)
Over the past couple years, the New York City-based web link-shortening service has become the most popular way for social media users to compress long URLs so tweets with links can fit into 140 characters. In addition to its link-shortening service, offers the ability to view statistics about users who click on the shortened links.

There's not yet any reliable information on how profitable is or even how it generates revenue, but it does appear to have attracted at least several million dollars in venture capital from private investors, who'll want a return on their investment at some point. That return may stem from advertising revenue or profits from the sale of information about those who click on links generated with

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The Bottom Line
HootSuite, RockMelt, TweetDeck and are four of the top providers of social media "infrastructure" that make websites like Facebook and Twitter possible. Whether they know it or not, most social media users rely on companies like these to get the most out online social networking. If you'd like to invest in such companies, keep an eye on them in case any decide to go public. Of course, to get in on TweetDeck, you'll need to buy stock in its new owner Twitter when that company finally moves ahead with an IPO. (The initial valuation of an IPO can determine the success or failure of a specific stock- but how is that price determined? For more, see How An IPO Is Valued.)