We already know that Barack Obama won South Carolina on Saturday by a huge margin. Duh.

The outcome may be no surprise to those of you following Yahoo's Political Dashboard, who would have have seen Barack Obama dominate online buzz in the run-up to the South Carolina primary. But what explains Obama's skyrocketing numbers and Hillary's dip on the day of the primary?

Voto Latino combines the telenovela with voter registration; the brief rise and fall of Unity 08; why are we seeing such a rise in Democratic voter turnout?; the Clinton Spendometer makes an outrageous claim about Hillary Clinton's spending proposals; Barack Obama is raising a ton of money in the aftermath of South Carolina; the Obama campaign continues to an email issuing from a dark place in America; and Hillary again responds to supporters' questions in a new video.

Our friends at Eventful have released some good news about the candidates' use of their site to organize local events in the runup to the Nevada caucus and South Carolina primary.

Yesterday I posted data from Yahoo! Buzz that showed Mitt Romney topping searches among Republican voters in Nevada and much closer numbers among Romney, John McCain, and Mike Huckabee in South Carolina. Now some data about Democratic voters in Nevada and South Carolina suggests a dead heat between Clinton and Obama.

Managing placements of online ads can be a challenge, as the Obama campaign recently learned. With more caucuses and primaries approaching, his campaign accidentally placed an ad for Nevada on a South Carolina TV news website. This seems to be an isolated incident. Fortunately, online ads can be swapped or pulled in ways that print ads cannot. The ad is no longer displayed on the News 14 website.

A connection between the Romney campaign and an anti-Fred Thompson website; the College Republicans are encouraging their minions to use YouTube; Mike Bloomberg's social networking profiles have been slow to take off; Rudy Giuliani is looking for ex-employees to shoot promo videos; Fred Thompson is out with a new and slow campaign video; and Hitwise stats show a huge market share for Thompson's website.

Reacting quickly to Facebook.com’s newly launched open API, the Obama campaign is the first of the presidentials to take advantage of the opportunity. Basically, anyone can develop an application that can be installed into your Facebook profile. So, just as you can use default Facebook applications like send a message or poke a friend, these new applications become another application on your Facebook homepage and interiror pages.

The Obama application can be used by a Facebook member to quickly see what is new with the campaign (video, messages, etc.) and forward these to their Facebook friends who live in the early primary states: NH, IA, NV, and SC. They can easily use this feature to share campaign videos and messages with their own friends out there, beyond the members of the Obama community. In other word, it makes spreading the campaign's message by virtual word-of-mouth that much easier.