In my niche, for the time being, the Zombie's have been held at bay for the past 3 days.
When they do arrive, sales conversions drop off the charts for periods of 6 or more hours, morning, noon or night. During those times visitors are coming through the "side doors", or sub pages. Many are foreign.
As I explained long ago when I first mentioned Zombie Traffic, I have door bells on key pages throughout my site so I can monitor my site activity without even looking. When these periods of poor conversions start, the doorbells go silent, traffic levels remain about the same, serps don't change at all and I have not made any recent changes to the site. It just appears that people just stop buying for no real reason. I attribute this to non-targeted traffic aka Zombies.
I know my market well, I know my traffic patterns well (by sound) and all of this started after the May Day update. Prior to that time, I enjoyed years of mostly trouble free traffic. When things are running "normal" I can go for weeks or months with the same consistent conversions. But at update time I can hear the change. I then come back to WebmasterWorld to see what's up and sure enough there is another algo update announced.
We all panic when these updates are announced and many see the same outages I see, some do not. However, after all of the recent updates (BTW - Panda had very little negative effect on my site) the pattern seems to remain the same....serps remain basically unchanged, sudden loss of traffic quality, then slowly things come back to normal. I believe it's more of a system loading issue (as mentioned in my last post on the April SERP topic).
The bottom line? I really don't see a point in trying to track down specific reasons because in the end it all remains a big black box and we'll never know if we are right or wrong (which is what infuriates many webmasters), so we're just chasing our tails.
As far as traffic throttling: This seems to be a separate issue that occurs during "normal" traffic quality periods. I've examined sales numbers from years back and they showed "natural" sinusoidal variations over weeks and months, and were increasing ever so slightly ever year.
Again, after May Day, patterns became almost "square wave". It's rather odd when you get consecutive weeks of exactly 15 sales per day, every day. Not sure how they know I made a sale because I do not set conversion target pages. No matter, I'm sure they know.
Now days, sales are either the same or lower than previous years. Oh, and my content is usually more popular when the economy is slow and gas, food and beverage prices are high, so the economy angle makes little sense. My competition has not changed, in fact we lost a few competitors.
Is traffic shaping intentional? Only Google knows. One thing is sure, there is no shortage of conspiracy theories for throttling. I'm not sure the two are the same. Or is shaping just the PC version? ;^)
The good thing is that once the smoke clears from these major updates, we start clicking along fine again. I'm happy to say that none of the major algo updates have had any lasting negative effect (other than the apparent throttling) on the site. At least we're still in business.
I think I need to look into nutmeg's zombie bot topic...
Looked into it, it does not appear apply to my situation.
[edited by: backdraft7 at 2:19 am (utc) on Apr 11, 2012]