Obama harnessed people who had not in the past joined a political campaign. He connected people, created communities and give them meaningful jobs to do.

I take those as the two key points from the article as quoted - engagement and activation.

Obama used the Internet to make people active and to continue the conversation in their neighbourhoods. Looking at simple statistics like the number of people contacted is a hang-over from traditional media advertising models - eyeballs win the day.

Where the Internet can really deliver is in it’s ability to facilitate and encourage the actions of many around a single idea. Content, as you rightly say, is the fuel for that process.