I have a website: www.example.com. ("www" is the preferred version, as declared in .htaccess as a redirect, the redirect works)
Somewhere along the line I declared both example.com and www.example.com as "owned" sites in my Adsense console.
On a few days over the last 2 weeks, I've had days where my reported Adsense pageviews were 2 to 4 times normal levels.
I've finally figured out that Adsense is reporting extra pageviews have come from example.com (the non-www form, which due to my .htaccess redirect, shouldn't ever be receiving any traffic at all).
Curiously enough, none of the errant non-www adsense pageviews ever generated any clicks. So it wasn't some type of click-bot thing.
Also adding to the puzzle, when I look at my server stats as reported by my hosting (Webalizer), none of the extra pageviews reported by Adsense show up there (and similarly hits, files, visits, sites, kbytes all look normal).
It's as if pageviews of my site are being shown, just on some days, massively so, but not by my server.
In fact, if it wasn't for my Adsense report, I'm not sure how I would have ever known any of this was going on.
Any ideas about where the cause of this issue lies and how to resolve it?
As far as my Adsense reporting goes, I've removed example.com (non-www) from my "owned" sites list, so I don't think I have any issues there. I'm more interested in what the motive here was, how it is done and how to stop it.