MIT researchers who studied Twitter's early growth suggest that the main source of initial growth was through media attention from traditional channels, and not a viral social media-driven phenomenon. The viral aspect of Twitter emerged as geographically-tied traditional social networks began utilizing the new technology.

"Nobody has ever really looked at the diffusion among innovators of a no-risk, free or low-cost product that's only useful if other people join you. It's a new paradigm in economics: what to do with all these new things that are free and easy to share," says MIT graduate student Jameson Toole, a co-author of the paper.

The paper correlated usage spikes in Twitter to media mentions and stories, and found them closely aligned. For instance, the most recognized media event was Ashton Kutcher's challenge to CNN for first to reach 1 million followers. This was followed by an appearance on Oprah's show, and large spikes in new users.

Until the researchers factored in media attention, their growth model based on early adopters and influencers could not adequately explain growth spikes. But once the media was factored in, the growth patterns began to make sense. Even in a connected, fast-paced and Internet-driven world, public relations is a strong growth driver.