Zillow Showcase Ads: Are their numbers fudged?

In putting our house on the market (Guilderland House for Sale), I posted information on a number of real estate websites. My first choice was Zillow, because I like the site myself, including the Zillow iPhone app.

One of the things I decided to try on Zillow is Zillow Showcase Ads. I was reviewing the numbers today and found something disturbing.


Zillow says that my showcase ad has had twenty clicks. But I'm not seeing these results on the other end:


Per Google Analytics, I've only had four visits from Zillow at all, and only two of them came from Zillow ads.

Is Zillow fudging the numbers for its Zillow Showcase Ads? Please post comments. I'm interested to see what others have experienced.