The common wisdom is that BarackObama.com is not only better at wrangling donations from the faithful, but is categorically better than JohnMcCain.com because it embraces an interactive as opposed to a broadcast model. Time's Michael Scherer put it this way last April:
Even today, if you go to McCain's website, you are more likely than not to find a page that just asks for money and broadcasts the campaign's message, with issue papers, press releases and videos.
By contrast, Obama's website is engineered for engagement: prompts invite people to volunteer, make phone calls and find nearby events. "Don't just fill out this volunteer form and wait," it reads. "Get started on your own." The blog is maintained by a former journalist; the social-networking function is managed by a founder of Facebook.
I don't disagree as far as BarackObama.com's depth of content goes. But let's not kid ourselves. At its core, BarackObama.com is not truly interactive. It is transactional.
The first time you hit the Obama website, you'll get a splash page prompting you to sign up for the email list. This is good practice, as the sign up form can get lost in the message-of-the-day clutter of the homepage. This way, you can change the homepage at will while still focusing on the most important thing: getting new people to sign up.
But the difference on BarackObama.com is this: the homepage above the fold hardly ever changes.