Advantages for Reviewers
Bottom line, you get very little out of reviewing at the moment: you don’t get paid, you don’t get acknowledged, your work goes into a blackhole. The only real advantage, is you get to read papers before they are published; it’s a service to the community.
With knowledgeblog, on the other hand, your reviews are public; perhaps, a bit scary at first, but it means that your comments, your ideas have your name attached to them.
You retain copyright on your comments; if you want, you can even keep your reviews within your control, on your own blog.
If you don’t understand something in the paper, if you need a point of clarification, you can ask the authors. You don’t need an intermediary to pass questions along. And you don’t have to cope with an irritating reviewer website.
Submissions are public; authors already know that anyone can read their article. This is likely to discourage the few authors who submit unfinished work, or who seem to treat the review as a free copy-editing service.