Google dance is a phenomenon where the page ranks of a website continuously fluctuate when Google is updating its servers. This is a practice used by the Google to ensure that its page ranking is always up to date and is in accordance to the merit of the various web pages.
Whenever you are maintaining your website, you have to keep in mind the Google dance phenomenon. If you can achieve a high search engine ranking for your website, it is necessary that you sustain that increase web site traffic. You should keep your website up to date with all the latest news and releases. The popularity of the keywords keeps changing from time to time. Thus, if you have increase web site traffic for a particular set of keywords, that does not guarantee that your website will sustain that increase web site traffic. You should keep a track of change in popularity of keywords and implement a search engine optimisation campaign. This is because when the Google dance takes place, the page ranks tend to change and this might drop your rank for some new set of words. Thus, you should keep your web content updated with latest keywords.
When the Google dance takes place, the page rank of a particular website moves to extremes before coming to its real page rank. This will see your website get a very low page rank in spite of the fact that you have increase web site traffic or the other way. Also see to it that Google has latest links of your website in its cached links. This is necessary because if you do not have your latest links in the cached pages of Google, even if you have good content it will not help you in increase web site traffic. Thus, if that is the case, you should re submit your site map to Google. This is a very useful search engine optimisation strategy.