Now this was something that got me.  I was reading over at Problogger about this, and the thought of it literally chilled me to the bone.

We all know that Google has a whole lot of reasons to kill your page rank, and most of them are things you’d deserve a penalty for.  If you’ve been selling text links, for example, or anything else that might be in violation of Google’s guidelines.  But what you may not know is that, at some point, for little or no reason, Google might kill your page rank and you wouldn’t even be responsible.

As it turns out, most search engines–and this includes Google–occasionally undergo changes to their algorithms, and when this happens, you might suffer an unaccountable, and unexplainable, loss in rank.

Now, this is for the most part generally temporary.  But if you should ever find your post ranking suddenly crashing, don’t panic.  It may well come back entirely on its own after just a couple days.  So take a deep breath, grab a drink, write your posts like normal and wait a couple days.  You might be surprised by what comes back.