This is what happened - one of my sites is ranked on the first and third page of SERPs for two particular keywords respectivelly. I checked them on Monday (Jan 30) and my site was there. On Tuesday and Wednesday it was gone - couldn't find it in the first 200 results

Yesterday checked again - my site is in the same positions as before. As nothing happened. Anyone has any idea what is going on?

Thanks,
Maggie

Maybe this will shed some light.
(google infrastructure change)

I'ts pretty normal - during the Google dance some sites gaining/losing positions for some time and some even disappear for some time but after a while everything is back to normal

I've seen many examples like that during last 2-3 years

Just wasn't sure if there is an update or not. Many thanks for your help

This is common with Google. Don't worry about it.

I just moved from 10th page to the first page for the term Programming forum.

how long does this 'dance' last?

There is no "dance"

This happens continuously and it is simply different datacentres answering the search query.

yeah i looked at 4 different datacenters for the same term... each had a different number of results. And when i was ranked #5-6 on page 1, now i'm on Page 60.

I checked one of my sites with a generic keyword at home (Bellsouth) and at work (local host.) At home, the site comes up on page 25, while at work, it come up on page 37. While this in itself may not be odd, the fact that its been this way for almost a week is. Guess you would have to call this a slow dance

I see this happen on a monthly basis - I am top 5 for a a few very competitive keywords, for 2 days a month I will drop to the 2nd or 3rd page and then bounce right back.
I can typically know that it is happening by slower sales before I ever check the SERPS.