If you initially get a bunch of links that none over say 6 months that could cause a decrease in PageRank, it may be because some of he initial links are removed or no longer counted.
When there is increase in the number of backlinks originating from a page.... the PR juice gets distributed evenly on more links, causing a drop in the value of PR juice flowing. This reduction in PR on a site then has a cascading effect on the links/pages that follow/backlink from it, causing drop in PR in lot many sites! Regards, RightMan
I think if some links are removed especially when you made links from a community sites then the link was remove the rank of your site also decreases.
Link sales or if there is a decrease in the backlinks to the page are the two main reasons you would drop PR.
You lost links, or your links has less PR because them lost links, or your links' link lost PR because them links lost them links
There are a lot of reasons 1. Your acquired links PR were dropped 2. Your acquired links PR not dropped but has too many outbound links 3. Your own pages has too many outbound links
If your number of backlinks has been reduced or if the page rank of your backlinks have been decreased.
I didn't think it really decreased that quickly? I feel like as long as your website holds a decent status of backlinks from high PR sites, you shouldn't notice decreases
I think the quality of backlinks, quality and timeliness of your page contents would be the top reasons behind a PR fluctuation. Thanks,