Lots of things, in generaal google penalizing your site. For example: Linking to a bad neighbour hood blackhat seo Will probably cause your site to suicide .
I guess mostly when people delete your back links, if your website is considered SPAM or MFA by Google, duplicate content, adult content (I think..), that kind of thing.
The points raised by AnOnYmOuS are relative but also lack of general site maintenance and uptime may also affect the site, plus many other factors may impact the PR, that will no doubt be listed as this thread continues
Some other reasons : Duplicate content Decrease in backlinks(already mentioned) The PR of the pages linking to you decrease One way links change to recp. links makes links less valuable making your PR decrease. Using Automatic Link Exchange Scripts.. These aren't all, but they are some .
They are not the same at all. SEs consider recp. links as almost wortheless and doesn't show that your site has good quaility content while one way links are considered as votes for your site, showing that your site is good. Recp. liks are usually good for traffic not SEO purposes. Or so I think ...
No IBL's or IBL's that are either deemed bad by the se or that become bad or non relevant afer google updates is weighting strategy like they did recently. You need tons of relevant IBL's to have a good PR. Most will tell you that there are tons of other factors, which to some extent their are, like your site being down, but 95% of PR is derived from quality incoming links whether they be recip or one-way.
I do'nt think this is correct. There is nothing wrong with having recp. when it comes to pr. That is part of the pr system, page A voting for page B and so forth. The reason you would loss pr is if you lost your backlinks because that is where the pr comes from, like wise if the pr of your backlinks drop so will yours, but only bepending on the site that took a pr drop. If you link to a bad site then google can penilize your site pr and put you on stand by till you fix it. Uncoverthenet was a good example of this when they linked to a bad site then watched their pr drop from 8 to 0. But if you fix things which they did then google will give you back the same pr you had before, even without having to wait for a update.
In my experience, anything from changing headers, page titles, URL/internal file structures can cause PR to drop. It's a good idea to use keywords in the URL...this is pretty obvious. I've also found that hyphens will reduce page rank very easily. I would rather have a lengthy, not-so-catchy URL/internal url than something with hyphens in it.
I never said recp. links cause less pr. What I said was one way linking changing to a reciprocal link will cause less PR, and I believe this makes sense . Glad to know what you think.
No offence, but I do not know where you got this information from it is not correct in anyway. Changing a one way link to a reciprocal link does not affect your pr at all. If anything it will help your pr. The only reason that pr will drop from a site are follows: 1) Loss of backlinks. 2) Increased number of outbound links from the site in which the pr is coming from. These are the main reasons you would lose your page rank. A few others have already been noted. The qoute above is far beyond the truth, none of those things will affect your page rank, it will only affect your search engine rankings. Sorry Rachna06.
If you stop working on your site.. you'll see it will affect your PR in the long run. If you keep getting links for your site, reciprocal or non-reciprocal, and keep adding new pages and content to your site, it won't fall. Also, we experimented once... we had 2 mirror sites, which had PR 6 both. We removed the mirror because Google has started penalizing the sites for duplicate content and the PR dropped to 5 for both sites.
a mixture of different types of link is always better Recip link are still useful but not as good as a one way link.