I only have one lens and it's very new. As I have posted it here and in some places, I don't know if it is a good indicator. Also, I have been editing a lot my own store at Zazzle, and I suppose Google Analytics capture this too.
Taking the last week, I had 16 direct visitors (myself?), 14 visitors coming from Shutterpoint (I have my Zazzle store in my sig there), 8 from Zazzle forum, 3 from Squidoo and 2 from here.
I also have two I can not explain (from Flickr and a t-shirt designer marketing his Zazzle products). I believe these two were people coming to Zazzle from sources not related to me, but who eventually ended up in my store.
The vast majority of my visitors are from Brazil (again, myself?) and USA.
PS: I'll do some work on my store this weekend and then leave it quiet for a while, so I can record more neutral results.