To the best of my knowledge, this is some sort of strange snafu where the keywords used from adsense traffic on other sites gets recorded incorrectly.

I could be completely off on this, though. Not sure.

I don't think it's adwords because our ads send visitors to landing pages on another domain.

I've seen similar things before on tracking codes. So I'm wondering, depending on where you are seeing it, if it's simply a reference attached to a link to your site from someone elses.

Where in Analytics are you seeing this? For instance, Is it being noted as a referrer? Is it being appended to popular content pages?

For us, it's showing up as the keyword.

For us, it's showing up as the keyword.

0278f9cd726373d18fae5988b846d1ba is what shows up in my keywords and has been hit 28 times. Is it robot activity I wonder...

more keywords ....

632979b747f33ffcd60354e60eb2e1509ca4ae556ee8fa21 n=9
84a8e0c9506ebaadd00fece9beab1c141bc057b0286c34c4 n=9

googlesyndication.com 154 23.1%
000000 96 14.4%
555555 10 1.5%
other 9 1.3%
444444 8 1.2%
666666 6 0.9%
333333 6 0.9%
ffffff 4 0.6%
e33f5e 4 0.6%
58595b 2 0.3%
000099 1 0.1%
search machine 1 0.1%
424242 1 0.1%
53a0df 1 0.1%
ffbbe8 1 0.1%
50646b 1 0.1%
ff9900 1 0.1%
d7bca5 1 0.1%
00ff00 1 0.1%

Boy, that sure feels like a waste of money spent on AdSense!

When auto-tagging is enabled in Adwords a 'gclid=' parameter with a long alpha/numeric identifier is appended to your destination URL automatically.

I've found that in some cases our Analytics tool will display this query string/gclid value in place of the keyword, for whatever reason.

Also: If you advertise on the Adwords 'Search Network' your ads are distributed to Ask and AOL by Google automatically--this would explain why these strange values appear to be coming from those engines.