Yeah that's a tough question as Lisa said. I'm the example of a person NOT to follow.
I've had my site for nearly 3 months now and I only have a few pages up - mainly because life issues have kept me from staying focused.
So I will be the one that it takes a lot longer than Lisa's story.
The point I want to make about sbi is that it works but you have to work it. You still have to write your content, be creative with your ideas and market your site. sbi just gives you the tools ALL IN ONE PLACE and it makes it easier.
For example all my sitemaps are updated at all times automatically so I don't have to manually do it and sbi submits them all to google, yahoo and msn sitemaps for me. My newsletter manager is all built in so I don't have to outsource with Aweber or any other company. I love having everything right there but the timeline for success really depends on you.
It's a great system though. Good luck!