It is believed that more the no. of backlinks, the better the PR, but is it really so ? I have seen websites with less backlinks scoring high on PR, and the ones with higher no. of backlinks scoring lower.
I think it has to done with content and linking out too. I noticed that when I place high pr sites with my niche on my blogroll my site's pr went up. One thing is for sure pr has nothing to do with ranking.
Yes It is, But u have to build Quality Back link. If u do linking with Non Quality site There is No benefit. Some Sites Have few back links but they have High PR coz the Back links of that sites are coming from a Quality and Powerful sites. Try to do niche related Back link Building then u don't need thousands of back link for High PR.
One good PR7 backlink from an established site in a related niche is worth more than loads of PR0 backlinks from directories or forums
"link juice" is what counts most. Every backlink have his power and it doesn't matter just which pr in on that site. Bigger pr it is, more juice that backlink have. But if there is more links from same page to different sites, that link juice is divided between that sites. It's like this: backlink from pr 6 counts much more then backlink from pr2. But if you are the only one having backlink from that pr6 sites counts much more if there is more sites linked from that page. Internal links takes that juice power too.
It is all about quality over quantity. So get some quality backlinks (which is most hard part) and you will get some great PR juice from google..