Online Systems for Behavior Change

I've always believe that to truly have impact on performance, we need to be experts at Behavior Change.   I've written a few times over the years on aspects of solutions that ultimately drive a change in behavior that leads to performance improvement.  I'm now working on an very interesting project that is designed to lead to some important changes in behavior that has already had dramatic impacts.  But we want to push for more, so ultimately this post is asking for help, please comment or tweet (add @tonykarrer) on:

What online systems have you seen that ultimately drive behavior change?

What do these systems do that leads to behavior change?

For example, there are solutions out there like:

• http://www.sparkpeople.com/
• http://www.jennycraig.com/
• http://yogaonline.corepoweryoga.com/
• http://poweroftwomarriage.com

that look to be interesting - although I don't have insights into specifics.  I would love to compile a list of other such solutions.  I also would love to hear about aspects of these systems that you feel drive behavior change.
Going back through my own writing/thoughts, it's remained fairly consistent over the years.  In Data Driven, I said:

If you want to really improve the numbers via a performance improvement initiative then you need to start and end with the data.

This solution relies heavily on humans to push each other to ultimately change behavior.  Using data as a means of assessing how you are doing from an action and results standpoint is an important aspect.
This is reinforced by Goals Accountability and Social Support for Big Impact where I used the responses to a monthly Big Question to arrive at the following as the basis for driving behavior change:

• Guide through setting meaningful personal goals
• Teach how you can hold yourself accountable to those goals
• Help the user set up social support
• Teach the social supporters how they can help hold the personal accountable
• Send lots of reminders to the individual and the supporters

When I've looked at other articles on Behavior Change, I found similar kinds of conclusions.

• Need to Change Behavior? Just Follow the Wizard

Most of the behavior change strategies, however, boil down to the following three “levers”:

1. Increase the number of triggers leading to the desirable behavior.
2. Enhance ability to perform the behavior (make it easier to do)
3. Amplify motivation for doing the behavior with intrinsic and extrinsic motivators.

• Design For Behavior Change
• It's All About Behavior Change
• BJ Fogg A Methodology for Designing Behavior Change

I'm definitely a big fan of The Power of Habit book.  I think there's a lot to be learned.  But for right now, I'm most interested in how these translate into online solutions that change behavior.
Please contribute and I will post back more on this.