Wow this looks very well thought out. One small thing would be that the image of the browser in the mac at the top of the marketing site is very hard to see. I always like being able to see up close what the product looks like. I suspect you can increase engagement/conversions simply by blowing that image up or just zooming in on part of the browser window there.

Also, once you click demo, things get a bit confusing. If the demo users need to go to http://demo.smoothbulletin.com/admin/ to actually start testing things out, make that a clickable link and call attention to that so users know thats where they need to go right now.