Site Build It's Integrated Features (Content 2.0, RSS/Blogs, Mailout Manager, Forms, etc.)My Site Build It Customer Review
Site Build It automates the creation of things like Content 2.0, RSS/Blog feeds, contact and feedback forms, mailout managers for E-zines, and autoresponders.

If you're new to internet marketing then you might not know what all these things are. That's totally fine! But trust me when I say that they are invaluable assets, and SBI makes them easy and painless. Imagine trying to learn how to use an autoresponder on your own, coding it into a website, and then managing the list as well as writing the emails you're going to send. Sound like a headache? It's not so bad once you've done it a few times, but if you're starting from scratch it's a tough learning curve. SBI will take the learning curve and throw it out the window, leaving you time to do other, more important things.
Yep, this is one of the areas that makes the yearly price of SBI look cheap.
Autoresponders themselves are highly valuable and effective, but people don't use them enough because they don't really know how.