Continuous variation of a keyword

[j0a0vargas]

Lords, on a site i have optimization job, a specific keyword, for over 5 months, ranging from 7 to +100 position. One day the keyword is there, beautiful on the first page, and another day disappear.

I do not understand why this happens, someone has something happened? I can not stabilize it, and is one of the most important for this client.

I live in tension, in the morning the first thing I do is search to see whether the keyword is.

Obviously it did in the first 2 months, then relaxed as she always comes back : )

Anyone have any idea what might be happening?

[EGOL]

Are you familiar with "personalized search"?

Just askin' because some people experience what you have described when logged in and logged out of google services.

[j0a0vargas]

Yes, it is no login, browse or rank, or cache. Variation occurs also in monitoring keywords campaign of seoMOZ.

[AlanMosley]

This is not uncommon, is this a very compeditive term?
The more compeditive a term, the larger the movement for a simple change, or lost link, or new link.

[j0a0vargas]

What I find strange is the keyword disappear for a day or two and then come back, often.

Normal would not be lose her position and then win or vice versa?