A term that refers to
Google's monthly update of its indexing and its page ranking. Part of the way Google determines relevance of a page is if other pages with a high
PageRank link to it. For example, if your page is about George Bush, George Bush is in office, and whitehouse.gov links to it, it will probably come up pretty high, much higher than if analteens.com links to it.
Once a month the possibly good people at Google adjust the PageRank figures. Your page might come up number 1 one month but number 300 next month because Google has shuffled its page ranks. During the Google Dance, your page relevance can also
fluctuate. It takes about four days for all of Google's servers to synch up with the new index and the new page ranking. So people who obsessively check their ranking and what order their pages come up tend to refer to this phase when their placements wildly fluctuate as Google doing it's little dance.
PageRank has created a search engine spamming problem called
Link Farms. Let's say one day you notice Google has given your page a very, very high page rank. Pages you link to, Google will then
percolate up to the top of the heap. You might be tempted, then, to charge people to get a link blessing from your page. Well, people do just that. However, since PageRanks can drop, you might be
SOL. This is particularly true if Google notices your page has ceased being anything but a link farm. Link Farm
scum fear the monthly Google Dance.