It's labelled "visitor", which is even more bogus (most measures might discriminate browsers, cookies, or IPs, which adds systemic errors in both directions).

It's labelled "visitor", which is even more bogus (most measures might discriminate browsers, cookies, or IPs, which adds systemic errors in both directions). According to jcampbell1, this is requests per domain from a traffic sample intercepted by ISPs, which means that Facebook like buttons and Google +1 buttons dominate. All we have is a 47% or so change in how many of those ISP logs contain +1 buttons.