I just noticed significant changes in my results in the last day or two. On one of my biggest keywords I had been consistently ranked 6-8 (on first page) for months. Just recently I popped up to 3-4. On another keyword phrase, for another site, I was not ranking at all and got some weird results this morning. I did a search on that keyword in FireFox (my main browser), and my site was #6. I did it a few minutes later and nothing. Then I tried it in Camino (Mac browser) that I rarely use and do not associate with my Google Account. Didn't rank. Then a few minutes later I ranked #3. Same thing with the same site for another key phrase. Is it possible Google is doing a big update? I do everything super white hat, so I'm a little excited.
No, what I'm seeing is different. I monitor my keywords almost daily. These are substantial changes I'm seeing.
Could be a lot of things... It could be a ranking algorithm/indexing algorithm change... could be that they've suddenly deindexed a lot of site that link to your URLs... could be you've gotten referred to a datacenter where they are trying out some changes or which is out of sync with the others. who knows. I would just monitor it for a couple of weeks and see what happens.
I think the "datacenter ... trying out some changes" is a good guess because the results are inconsistent.
Yep I agree maybe its another form of Google dance. You are lucky that your sites are going up. Some website go down with this dance.