This is a pretty interesting read. You have to download a pdf. Back when Obama was running for President nobody had ever leveraged technology, social media, and the internet the way he did as much of what seems commonplace today was in it's early stages back then.
www.gsb.stanford.edu
In terms of the numbers, externally, Obama’s campaign was able to garner 5 million supporters on 15 different social networks ranging from Facebook to MySpace. By November 2008, Obama had approximately 2.5 million (some sources say as much as 3.2 million supporters, outperforming Republican opponent John McCain by nearly four times. In terms of Twitter, Obama had over 115,000 followers, more than 23 times those of John McCain. In terms of YouTube followers and clips, people spent 14 million hours watching campaign-related Obama videos on YouTube with 50 million viewers total. That was four times McCain’s YouTube viewers.
The campaign’s internally created online social network,
www.my.barackobama.com (MyBO), allowed individuals to use technology and web tools to connect to one another and to activate themselves on behalf of the Obama campaign. Two million profiles were created on that site. Registered users and volunteers planned over 200,000 offline events, wrote 400,000 blog posts, and created 35,000 volunteer groups through the site.