I have a question.. How to restore PR from 0 to what it was before? Why do sites get downgraded to 0? Please advise... Many thanks!
If you was selling unrelated links (DoFollow) get rid of them or simply use the (NoFollow) tag.. You have to take off any spamy technique you've used in the past and then request a reconsideration in WMT. Ex. Duplicate content, Doorway pages, Cloaking, Selling links (dofollow) etc.. Hope i was helpful, REP is most appreciated
You probably lost your pr because you were penalized for doing something wrong you have to review google's rules and thoroughly inspect your site to see what may have cause this penalty. When you have found the problem you should correct it and submit a re-inclusion request to google through google webmaster tools.
I don't agree with any of these posts. I think links that were passing you PR aren't anymore. Investigate at once.
I once had a site PR5 that lost all PR due to a google penalty, it has gone 2 years and now it is back with a PR4 (last update) It takes a lot of hard work to make google trust your site again. That beeing said, the site still doesn't rank nearly as well as it used to.
Nobody can know exactly about this problem except Google. So, I am not sure but this is my way. - After Google update I check to know which sites lost PR - Buy a just dropped domain with a higher PR - Make a quick site for it - Set back-links to my sites - Check if there are any broken links in my sites and remove it if any Please share your way!