Agreed completely. Not showing or telling a first time user in clear, concise language why the $&*% they're on the site is a great way to have a sky high bounce rate. If you worry about boring existing users employ tools like "don't show this again" buttons, cookies to know when they're returning users and present them their dashboard(tumblr does this very well) etc but don't alienate first time visitors if you want new users.
Great point. I see so many sites making this mistake. If you have cool functionality or content that you can show without a login then show it right away! If I can't figure out if I like it within 20 seconds, then I'll probably leave.
A buddy of mine suggested I post to HN, so here goes. I'd love to hear your thoughts -- or other examples of new products that had/have a UX optimized for the first-timer...
Hardware makers seem to have come around to this idea. Apple is obviously strong. I think the experience of getting a Kindle in mail that is already set up with your Amazon account is pretty great. I was a fan of the first time experience of the Doxie scanner as well. Simple, informative and cute/stylized.
For software, I was impressed with Ableton live. It would be a very daunting app to learn without built in tutorials and a module in the bottom left of the app that gives a great explanation of anything you roll over. Adobe sucks at this stuff, but they are the industry standard, so people slog through it. 3D modeling software could also benefit from some first timer love.