"takes LONGER to get your page rank higher if you are on wordpress.com"
Whoa, couldn't prove it by me: I was so confused when I first got a blog here I posted near gibberish --to figure out how it worked; one -two a day dribbled in to look. But within TWO months: WP blog is PR 5, with some posts returned higher on results page than institutions --technorati puts it among first half million of 57 million blogs they track. But not even one comment, on any page.
Another blog: about to have my one-year anniversary, over 100 pages, tons of traffic, bookmarks, comments --PR: 1
Why? Makes me crazy. I'm the same writer --for both, same grabbing-type headlines, same sarcasism (only the title and focus are different).... If I knew how/why I could fix the one with national & international readership.
Only difference between the two: higher PR is on WP blog. I suspect: Google Loves WP and their blogs....