Websites dance at various times under various conditions and sometimes we just don't know why. Well, there are a lot of different reasons they dance at different levels and I think exploring some of those reasons is a good idea for a discussion. #1 Backlink a brand new site with decent backlinks and not a whole lot of content and you'll dance. #2 Add a bunch of content and not a whole lot of backlinks and chances are there will be little dancing. #3 Add a bunch of content and a bunch of backlinks and you'll not likely dance but rather sink down in the rankings right off the bat. #4 Continue to add content and backlinks to #3 and you'll end up coming up in the rankings for a lot of different KWs. #5 Hit #4 with lots and lots of links and you'll increase your chances of staying up in the rankings with no dancing. #6 Use and abuse your site with even more content and backlinks (no matter what they are) and you'll be sending Google Christmas cards. Sites that have not been spammed with backlinks will dance more than those that have not and there is no reason to "fear the dance". It is sort of like puberty, you have to go through it and have to let it run it's course and once it has you can end up a very secure man or woman but it sucks going through the process. Once Google checks your links and sees that you are trustworthy, you'll have some very solid rankings and won't lose them because some upstart guy comes along with his latest and greatest website with a gaggle of backlinks as you have already established where you belong in the google algorithym.