Time is a factor. I will continue to monitor this, but this does not look like much of a major change from the background levels, certainly not over time.
Of course mentioning this skews the stats, so no reference to the viral marketing campaign nor to the originating site, but you can follow the link here and read the previous views here if this rings any bells.
I have done research and analysis, but not for some time, but these graphs would seem to support my view that although there has been an undoubted spike recently, it has not lasted nor did it have the lasting effect of the first campaign. I have also searched on both potential versions of the retailer's name as it has an impact on the results (as you can see).
Over 2 months
Over 6 months
As I committed myself to be a nay-sayer from the start, I am monitoring this with interest, but would be very interested to know more about the impact on sales (as opposed to mere "mentions"). I wonder if we'll ever get these?