A 2006 study by Marketing Evolution in 2006 for Magazine Publishers of America found that campaigns combining TV and web can create increased brand awareness:

"With TV alone indexing at 100, brand awareness increased to 138 when online was added to TV in the mix. This increase was the average across an aggregate of 20 studies, 10 of which had sufficient sample size to examine each combination of media.

Clearly, where affordable for ! a client, a media mix is beneficial and the addition of Web activity t o TV activity can increase both awareness and sales."

From MediaPost

Adapted from a reply I made on John Jarvis' Buzz Machine blog:

The Internet and cheap digital tools allow crowd-sourcing of news by amateurs, not just because the technology makes production and distribution fast, easy and cheap, but also because it diffuses risk through the crowd. So it makes any individual's share of the risk small enough to be acceptable, and makes the small compensation (recognition, fun, etc) acceptable as well. In the same way, the net itself has been made available for next to nothing by diffusing the cost (risk) through countless servers and routers.