Mystery: Old domain still gets 1 Adsense hit per day

[fredw]

A few weeks before the end of December last year, I acquired a new domain name and rebranded one of my biggest sites. (I wouldn't normally consider doing such a thing, but the definitive domain name for my niche was handed to me on a silver platter, and I am happy to report the domain rebranding did not adversely affect my traffic or ranking in my niche.)

As part of the rebranding, I added a mod-rewrite which redirects the old domain name to the new domain name.

It's 6 months later now, but still, on my Adsense daily stats, the old domain name gets 1 hit per day. Not two hits, not three hits, just 1 per day.

What could this be? Even though the domain still hits my server, because of the mod-rewrite it is impossible to end up at a page containing Adsense using that domain. Cached somewhere? But then, wouldn't it be inconsistently a few per day? Why always 1 per day? Even a hole in my mod-rewrite scheme would, one would assume, let people in inconsistently a few per day. But the count in the daily Adsense stats for this old domain is always 1.

Anyone have a clue why this would be happening?

[OutdoorWebcams]

Any clues in your old domain's logfiles?

[acac]

A google bug perhaps?

[fredw]

Webcams: I have examined my log files several times, once again yesterday. I never see any record as visited from that domain that could possibly make an adsense impression (excluding things like rss file hits) that isn't shown as HTTP status 301, which means the mod-rewrite is always working correctly, as far as I can see.

Acac: certainly looks like it, doesn't it? But I think we could guess this only if someone else has seen exactly the same thing.

[CWebguy]

Maybe a cached version of an old page?

[fredw]

Ah, but Mr. CWeb, why would such a cached page only get hit once a day, every day?

[Gibble]

Can you see what time the hit was at? Is it constant?

[fredw]

No, don't know, have never been able to identify the event in my logs...

[netmeg]

Could it still be listed with a webmaster tools account for Google, Yahoo or MSN, or some other directory or tool that would ping it once a day ?

[Bddmed]

A bot running on your or other ones local computer once a day with your old domain name mapped to a local server in the hosts file?

[darkyl]

I would notify the adsense team about this, explaining that you find those clicks "strange" and that it's not you clicking on the ads.

I always write the team in advance when I see weird stats in my adsense, and it's appreciated. It can also be a point in your favor in the case you run into problems in the future.

[fredw]

It's not that bad, darkyl. It's not 1 click per day. It's 1 impression per day. I never see a click on the old domain. Sorry if I could have been clearer.

Thanks for the ideas, everyone...