Appearing and disappearing from the index

[serenoo]

When I search for 2 keywords on google sometimes I am at position number 7. The day after I am not in the index. After one hour I am still number 7, then disappeared, then again number 7 ....
It continues in this way from more than one month.
What is the meaning of this dance?

[piatkow]

Now you know why the expression "Google Dance" has been around for so long.

How long has the site been established?

[serenoo]

The website is 8 months old, but I started creating page 4 months ago. Total pages: 16.
I rank in the first 20 results for any page, because it is a niche website (In my country there are no competitors, only big websites that have a sub-section about my same theme). But for 2 keywords related to my home page I dance everyday.

[Robert Charlton]

When you say "not in the index", do you mean that you simply aren't ranking... or that you've been completely de-indexed?

It's likely you've remained in the index, or you wouldn't be cyclically reappearing. It's possible you're seeing different "partitions" of Google's index... using the word partition very sloppily here, as we could be talking about data centers or about other ways Google might be dividing up its data... periodically switching back from one to the other. This might be different data sets that Google is testing, or it might be a glitch.

One of the types of things Google might be testing is localization. The serps for some queries are hyperlocalized, even where you wouldn't normally expect localization, and I've seen results come and go as I set my default location to places only a mile or two apart.

Google might also be testing different aspects of its algorithm. When you disappear, you might try searching in quotes for a unique five or six word text string on your page, to double-check that you're in the index.

[serenoo]

I mean I am in the index, but I do not rank. I tested it today (because yesterday my home page was #7 as usual) and I am not in the first 200 rankings, but if you go to rank number 245 you can find me, but not with the home page (that is the page related to the kewyord), but with another one.
That dance happens only with keyords for my home page.
What is the sense of this game?

[Robert Charlton]

See this discussion...

Homepages (on several sites) not ranking, internal pages are
http://www.webmasterworld.com/google/4551018.htm [webmasterworld.com]

Though the question stated withheld some important information, I feel the answers in the thread provide a good overview of possibilities. In the case you describe, where your home page is dropping down to #245, it's likely that your inbound links to the home page look spammy to Google. That would be my first guess.

[serenoo]

Thank you Robert for the link, I read it, but there the situation is a little different. They do not rank at all, while I rank only on odd days. :-)
Am I the first case of intermittence?