Maybe some mainstream media coverage regarding your niche? Check your logs.

I don't think that's it. The activity is across the board. All kinds of entry pages in the catalog section. It's like the raised my SERP position for about 10hrs.

This kind of thing has been happening for a while - but at a rather low level and not noticed by many. The first few that reported it sounded to some like they were a bit crazy, but it has proven itself to be real.

Related threads:

The Yo-Yo Effect [webmasterworld.com]
Google Traffic Throttling? [webmasterworld.com]

Since you're seeing a new spike, it sounds like you're one of the lucky ones who got the yo-yo UP from where you were. Let us know if you see another traffic spike from Google, please!

[edited by: tedster at 1:30 pm (utc) on Mar. 1, 2009]

I'm seeing a spike on one of the keywords that I track, -11 from 18 to 7 today.

Something similar happened on Jan 25 and 27 for the same keyword, from 17 to 8 on those days, and back to its "natural" position the next.

The keyword is an acronym for the geographical location this site deals with, and part of the domain name. Looks to me like G is testing if the topic of our site is deemed relevant enough by visitors when doing general "location" searches.

Edit: another site that I track just had this happen yesterday for "location widgets" - from 14 to 8 and back. Have not been monitoring this for long as it's a newly redeveloped site that has just appeared on my radar.

My observations may be off since rankings sometimes change multiple times over the course of one 24hr period and I only track once a day.

I saw my Google referrals double on one site last Monday. It hasn't exactly continued at that rate throughout the week, but there was still a noticeable increase overall. I can't seem to be able to pin this down to one particular keyword or -phrase, or even a few. Instead, overall keyword performance seems to have increased. That Monday would have been the new record if it hadn't been for a big spike in StumbleUpon traffic on Friday.

...like they were a bit crazy...

But I saw it with my own *twitch* t-two eyes!

Like clockwork, back at 17 today.

And 6 today - this is getting interesting...

Unfortunately, the term has only 1/3 of the search volume of the keyword that is generally used, and 740K results vs 5.7M for the main term.

On the other hand, the "competing" site was yanked to 23 - two consecutive downgrades...

Edit: for clarification, I'm using the Google SOAP API for this...

Edit 2: for another 2-word term, something I'd never hope to rank for because it's too general, I lost 36 positions today - dropping to 49. Since September 2008, the "natural" position is between 12 and 15, with two earlier spikes into the 40's on Oct 14-30 and Nov 13-25. Will look again in 2 weeks :)

Today's lottery numbers: site A from 6 to 18 and site B from 23 to 6.

I'll post back a summary in a week or so...

Well it's been a week of back to normal. Then today, about 2:00pm cst. Then it was double normal traffic, and at 3:00pm to 8:00pm triple normal traffic.

I also noticed that while I had incredible traffic last Friday with corresponding click throughs to Amazon, there was no corresponding up tick in actual sales.

Three days, Friday, Saturday and Sunday back at 5 times traffic, the Monday back to normal.

[edited by: BarryStCyr at 1:47 pm (utc) on Mar. 10, 2009]

Saturday and Sunday, both over 2000 uniques, then Monday back to normal.

Just ran a data center check, about half show over 1,000,000 index pages which is what has been showing for a couple of weeks, up from about 500,000. The others are showing about 22,000, a significant drop in indexed pages.

...Friday, Saturday and Sunday back at 5 times traffic, the Monday back to normal.

Offhand, this repeated pattern suggests two possibilities to me...
- that the rankings are changing on weekends...
- or that there are more searches for your terms on weekends.

I've seen evidence that both can happen...
- amazingly pronounced and predictable day/time-dependent spikes for certain kinds of searches...
- and I've also seen that Google rankings for some page and phrase combinations have changed on weekends.

Google first mentioned time-sensitive rankings a few years ago in one of their patent applications. In that patent they raised the possibility of time-of-day, day-of-week, and season-of-year.

I've been seeing this kind of shifting on a minor scale for a year or more, but it now seems that they're rolling out a much more intensive use of this approach.

Well it did not occur four weekends in a row. My traffic stayed at normal levels this past weekend. Now my index pages in google have dropped to about 128,000.

Guess the ride is over.

You dropped from 500,000 indexed urls to 128,000? That's pretty extreme.

What's your estimate of the total urls on your site?

I have over 2 million unique item numbers that have been referenced. The highest I have seen Google report with site:example.com is 1.4 million and that was in the last 2 weeks.

One day they think it's "the greatest thing since sliced bread," the next it's like "what's sliced bread."

Oh, well that the way things go. I dropped my crystal ball and now all I get is static.

If anything further happens I'll let everybody know.

It sounds like you're seeing different data centers at different times when you use the site: operator. If you use Firefox with the ShowIP add-on you would be able to tell for certain if that's the case, by taking note of which IP address at Google is serving up the particular results you see at any time.

Hmm, March 22nd or 23rd I think it was; one site with a single day 400% traffic increase, then back to normal since.