The Web site of the campaign of Barack Obama had 3.3 million unique visitors in June, double the 1.6 million uniques for the John McCain site.  Time spent per visit on the Obama campaign was over 11 minutes vs. 5:30 minutes on the McCain site, Nielsen Online has told Beet.TV

We believe a big factor in the the longer stays on the Obama site is the
popularity and accessibility of campaign videos, which are
prominently placed on the home page and easily found. We have published a speech by Michelle Obama from the home page of the campaign today. It is published on the Brightcove player.

Videos on the
McCain site are hidden under a multimedia category. There is very little in the
way of original video, mostly campaign ads.

The McCain videos are hosted by  For some reason, the “share” button on these videos is not enabled by the McCain campaign, so these videos cannot be shared from the campaign site.  (The videos can be shared on the campaign’s YouTube channel.)

A spokesperson for Nielsen tells Beet.TV that streams of campaign
videos on the Obama campaign site far exceed videos on the McCain site
.  We hope to publish Nielsen numbers on the video streams for both campaigns early next week.

The takeaway here:  To maintain audience engagement, give them video and make it easy to find.  And to drive video consumption, make the videos sharable.

Although McCain’s campaign site lags behind Obama’s, it is
growing more quickly, having tripled in one month.  In May, the McCain
site had 563,000 uniques in May vs. 2.2 million for  Obama, Nielsen reported last month.

— Andy Plesser