Compete.com a web stats site shows 1,478,149 visitors for the month of June for the US. That's around 42,297 visitors a day.
https://siteanalytics.compete.com/jw.org
If you imagine that the same individual will log onto jw.org on their smart phone, IPAD, laptop and home computer (which witnesses definitely do) many of these visitors will get counted up to 4 times.
Quantcast.com shows 866,986 visitors for the period of May 31st - June 29th 2014. That's 28,899 visitors a day. Again not quite a million.
I'm not sure the WT are measuring their stats but not one of the major web stat analysis sites agree with the figure mentioned above.
Still.. the number of visitors too is no real indication of how well a website is doing or how well it's material is received any more than the number of letter boxes tracts are pushed through is any real indication of people interested in what the org is selling or the hours spent knocking on doors is any true indication of how well people are receiving their message. These numbers in fact only show just how much sheer time and paper is wasted.