Sometimes you’ll find that if you do a search for a keyword your website will appear in position X.
You search again 30 minutes later and you see you’re in position XX.
3 hours later and you’re back in position X.
An hour after this and you’re in position X+5.
This is what is refered to as the Google Dance – your websites SEO rankings are not static, they bounce around and seem to be different every time you do a search.
Why Does This Happen?
It happens because Google don’t just have 1 big server like you imagine, they have many thousands of small linux servers all doing the work.
You search now and you’re connected to linux server 11139 – that has Google rankings database 99999 on it.
You search 20 minutes later and you’re connected to linux server 2271 – this has Google database 99998 on it.
3 hours later you get linux server 7412 – this has Google database 99803 on it.
All of them have different versions of the algorithm and rankings stored on them – ie your rankings – since changes ripple out slowly across all servers, not all at once.
So from your perspective your website is bouncing around or “dancing” when in reality what you’re really seeing is a different data set from a different server each time you search.
It’s all a bit like Albert Einstein’s theory of relativity – that is it’s all relative to the viewpoint of the observer – you.
You tend to see these big bounces or dances after you’ve made major changes to your website, or have seen some powerful links built to your website.
Until all of the Google servers catch up with the latest changes, your website appears to “dance around” because you’re seeing different results from (effectively) different snapshots in time.
It’s nothing to worry about, it’s perfectly normal.