I am not sure I understand this one. Jessica from Google posted in the Google Web Search Help forums asking forum members how they heard about the Google Zeitgeist.
She wrote:
With 2012 coming to a close, Google released its 12th annual Zeitgeist a couple of weeks ago. We're curious to know how you heard about it and you can tell us here. :)
You can see the form over here but I don't get why Google is asking a subset of users this question. Google has referrer data, heck they know more about where you've been on the web than you know yourself.
The form asks:
We're interested to hear about where you heard about Google's 2012 Zeitgeist (www.google.com/zeitgeist/). Please tell us below!Family member or friend?
Your social network, like Facebook, Google+, Twitter, or Reddit? A blog?
An online article from a source like NYTimes, Slate, Wired, etc.? Somewhere else?
Why do you think Google posted a form asking about this?
Forum discussion at Google Web Search Help.

Comments:
MonopolizedSearch
12/28/2012 02:41 pm
Google's analytics don't extend into the offline world yet. Who knows, a Google data/mapping chip may be implanted in people one day. :) But I suspect Google is looking for info regarding how word has spread outside of the internet.
@steveplunkett
12/28/2012 11:16 pm
they want someone to say Google +
CandleForex
12/30/2012 08:15 am
Maybe because it just more data to add to their profiling of everybody who has a google account?
Alex of Harford
01/02/2013 12:52 pm
Perhaps they're trying to find out how many people tell the truth in these surveys or how accurate their memories are. I said SE RoundTable and I'm impressed with my memory recall from 1 minute ago.
Jeff
01/03/2013 09:49 pm
I suppose the teams internally aren't really working together somehow.