Incresing online user engagement

I’m actually working on an on-line buzz campaign. While surfing I found this white paper by Steve Outing, of Enthusiast Group.
Steve suggests some tips to improve people engagement and participation..
A fast summary:

Tip 1 – Allow user comments on every piece of content on your website
Tip 2 - Make users know when their conversations evolve (without annoying!)
Tip 3 – Make celebrity editors or executives post comments: commitment affects.
Tip 4 – Have a human (preferably a celebrity) in position of community leader
Tip 5 – Develop an incentive system to rise users’ commitment and loyalty
Tip 6 - Promote volunteer manpower to help you moderating the site
Tip 7 – Give back. Contests can be a good way.
Tip 8 – Reward highlighting best contributions
Tip 9 – Produce a newsletter with most appreciated contributions

For the complete white paper go to Enthusiast Group Website
Anyone knows where I can find more tips and suggestions?