If your site is fairly new, and it is jumping up and down the search engine results page, you are experiencing what is known as the google dance. The google dance was eliminated in 20013, but with the recent Panda updates, it made a return.
When you do some on page or off page SEO, you will usually experienced a drop or rise in your rankings, then it will change, and maybe keep rising and falling a few times before it becomes more static.
I changed nothing, so why am i still moving?
Some examples of why you may be experiencing the google dance are as follows.
1. Increased social interaction. If for whatever reason you get more shares on facebook or tweets, google plus votes etc, you could see a jump in your rankings, which is great.
2. Higher ranking sites may lose ranking. Some sites that rank higher than you may be using black hat techniques to get above you, and when they are found out by google they get “slapped” or penalized meaning they fall out of the results page, and you move up. If you are in a competitive niche, and a lot of black hat sites get de-indexed, you can see huge increases in rankings overnight.
How long does the google dance last?
The only true answer to the question is “forever” as your rankings do not depend on your site or its seo/lack of seo, exclusively. The caliber of the sites above and below you will affect your rankings, but generally your site will move around for roughly one week before stabilizing.