Mark Zuckerberg - FacebookWe'll start with the most famous and successful of the social media magnates, Facebook founder Mark Zuckerberg. There's already been a lot written about Zuckerberg - and if you want a semi-fictionalized version of his tale you can see the aforementioned "The Social Network" movie - but in brief: While studying at Harvard and working out of his dorm, Zuckerberg started TheFacebook.com as a sort of student directory. Needless to say, Facebook has flourished into the biggest social network in the world.
Started as a directory, it is now a place to host photos, connect with friends, share stories and status updates, publicly proclaim your likes and dislikes, and it's also become a place for companies to engage in direct marketing. According to Forbes, as of September 2010, Zuckerberg is worth $6.9 billion. Though there's been a lot of controversy around Facebook, it doesn't look like the trend will be dying out soon.
Tom Anderson - MyspaceNot all social media trends last forever (anyone remember Friendster?), as evidenced in the growth and decline of Myspace. When you first signed up for Myspace, your first friend was most likely co-founder Tom Anderson, and before being surpassed by Facebook in 2008, Myspace was the biggest social media site in the world. Myspace is now known more for its music and video hosting and as a way for bands to promote themselves by streaming their media, and it still has many personal users. Anderson co-founded Myspace with Chris DeWolfe in 2003, before selling it to Rupert Murdoch's News Corporation for $580 million in 2005.
IN PICTURES: Consumer "Fads" That Haven't Faded
Andrew Mason - GrouponGroup buying, and specifically Groupon, has become a huge trend in the last year, capitalizing on the growing popularity of social marketing. Andrew Mason, a 29-year old music major and self-taught computer programmer, had a few startups before perfecting the recipe for online success with Groupon in 2008. Groupon has employees that contact businesses; these businesses then give a special offer that's only available through Groupon, and Groupon sends a daily email to people who are signed up in the business's city. It can be anything from 40% off clothes, to half-price dinners to cheap yoga classes, and it's really catching on. According to a Forbes article from August, Groupon is the fastest growing online company ever, and is set to pull in more than $500 million in revenue for 2010. (For a counterpoint, see 8 Reasons Why You Shouldn't Use Coupons.)
Reid Hoffman – LinkedInLinkedIn is a professional version of Facebook, where people use the social network site not to update what they had for lunch or show pictures from last night's party, but to network with about 80 million other professionals who want to advance their careers. An academic with a master's degree in philosophy, Hoffman was at Paypal before co-founding LinkedIn in 2003. According to Forbes, Hoffman is estimated to be worth $340 million, and LinkedIn has been valued at $2 billion.
Jack Dorsey – TwitterTwitter was created by Jack Dorsey in 2006, and the 140-character microblogging powerhouse now has more than 100 million users. Dorsey is a software engineer, and was the CEO of Twitter until 2008, where he is now chairman. He also runs the site Square, which is a portable credit card service that can be used with an iPhone. Twitter is a place where you can share your thoughts and daily activities, and point people towards links and news items - as long as you do it in 140 characters or less. (For more, check out Tweeting: The Next New "Profession".)
Bottom LineSocial media is not going anywhere, and at this point, it's still in its infancy. With the advent of all of these social sites, there are many options for individuals and investors to choose from, and if you can think of a way to improve or revolutionize these types of services, there's a lot of money to be made.