Zineb Ait Bahajji from Google's Webmaster Trends team was in a Google+ live hangout just a couple hours ago with Pierre Far from Google and attempted to answer a very popular SEO question.
The question was, why would your business/website rank very badly for one keyword? You can rank well for other terms but not for a main keyword and you can't figure out why.
Google's Zineb Ait Bahajji gave mostly the generic answer that Google's search results fluctuate and that is normal.
She answered the question at 16:52 into the hangout:
The answer is very simple here. It is normal to see fluctuations in SERPs(the search engine results pages). There are continuous changes in in SERPs and your competitors are also optimizing their web sites as well. So it is normal to rank number one and then number three and then number five, and then go back to number two. These are normal changes.My advice would be to just focus on your audience and build quality content, compelling content and unique content that is tailored for your users exactly.
So that is it, it is normal to see fluctuations.
Here is the video embedded at that start time:
Forum discussion at Google+.
