“A lot the political stuff online is really dry, but with Christie, there’s an entertainment factor,” said Nicco Mele, who teaches a class on the Internet and politics at the Kennedy School of Government at Harvard. “These videos don’t seem professionally produced, even though they are.”

Mr. Mele, who worked on Internet strategy for Howard Dean’s bid for the Democratic presidential nomination in 2004, noted that “until now, the most visible impact YouTube has had on politics is catching gaffes, but that’s changing.” He described Mr. Christie’s approach as “very smart and unusual” and predicted “you’ll see other people adopt it.”…

A Sean Hannity or Don Imus interview has a bigger audience, but experts say the influence of online video may be greater. People learn of the videos from trusted friends or bloggers, they can replay them endlessly, and they often forward the links to others; and they are likely to pay closer attention to something they seek out rather than something that washes over the airwaves.