Face Book & Twitter Social Sites

Social networking is conquering the Web, and the two leaders in this growing market are Facebook and Twitter. Each site has built communities of millions of users and developers in just a few short years, and they are fighting each other to become the top destination for Web users looking to share information with friends and colleagues.
Facebook, launched in February 2004, lured 135.4 million unique visitors to its site in April 2010 for a whopping 3.2 billion total visits, according to Compete, an analytics firm. Twitter, launched in March 2006, lured 21.5 million unique visitors in April 2010 for 147.4 million total visits.
Facebook is a social networking website where users can add people as friends and send them messages, and update their personal profiles to notify friends about themselves. Users can create profiles with photos, lists of personal interests, contact information and other personal information. Communicating with friends and other users can be done through private or public messages or a chat feature. Users can also create and join interest groups and "like pages" (formerly called "fan pages" until April 19, 2010), some of which are maintained by organizations as a means of advertising.
Twitter is both a social networking and microblogging service, enabling its users to send and read other users' messages called tweets. Tweets are text-based posts of up to 140 characters displayed on the user's profile page. Tweets are publicly visible by default; however senders can restrict message delivery to their friends list. Users may subscribe to other author tweets—this is known as following and subscribers are known as followers.
Users can group posts together by topic or type by use of hashtags — words or phrases prefixed with a #. Similarly, the letter "d" followed by a username allows users to send messages privately. Finally, the @ sign followed by a username is used for mentioning or replying to other users.
Facebook is clearly the most popular social networking site, and it trails only Google as the Internet site with the most visitors. If you don't count YouTube, the video sharing service, as a social network, then Twitter is firmly in second place, well ahead of additional rival LinkedIn, a business networking site that had nearly 13 million monthly visitors in April 2010.
While Facebook has a huge lead by the numbers, a growing user backlash regarding privacy settings could threaten the site's dominance. Most significantly, Facebook has rolled out new privacy settings that make more user content public, and therefore more like Twitter, where content is public by default. However, this strategy has backfired on Facebook, with users complaining that privacy controls are too complicated to understand and actually make it harder to hide personal information from non-friends. Facebook responded in May 2010 with a new set of privacy controls.
Just in the last week, Facebook announced new features to make it easier for people to share their updates selectively and draw distinctions between friends, family members and co-workers on the Web's biggest social hub. The new feature is called "groups" and it will allow people to set up pages consisting of people who share the same interests or family affiliation. Group members can post information that only other members can see, and they will be able to convene in chat rooms. Members also will be able to plan events together. But the ability to “tag” anyone and add them to a group automatically is not winning the company much support. For some, this feature appears to be another example of Facebook’s preference for automatically opting people in to new services by default and forcing them to opt out,
Twitter hasn't had to deal with the same type of privacy backlash because the company has always made it clear that tweets are intended to be public. Twitter collects personally identifiable information about its users and shares it with third parties. The service reserves the right to sell this information as an asset if the company changes hands. While Twitter displays no advertising, advertisers can target users based on their history of tweets and may quote tweets in ads directed specifically to the user. Users have the option of "approving" followers, thus preventing most of the public from seeing their tweets, but this is the exception rather than the rule.
Twitter has its own problems. Downtime has frustrated users on many occasions, although this has become less common in 2010. Twitter also can be an effective medium for spreading viruses, particularly with shortened links that hide the original source.
In fact, many types of security threats have plagued both Facebook and Twitter, including stolen accounts, worm attacks, phishing, botnets and spam, leading employers to be wary of increasing employee use of the sites.
Despite these security and privacy risks, Facebook and Twitter are undeniably on the rise. These rival sites are attracting attention from competitors, as seen in Google's unveiling of Buzz, which brings Facebook- and Twitter-like status updates to Gmail.
Many Internet users log on to both Facebook and Twitter because of the sites' different strengths and because they want to separate one group of contacts from the other. But Facebook and Twitter executives know that many people simply don't have the time or patience for more than one social networking site, and the battle for market share will only grow more contentious as the financial stakes get higher.