phranque - 10:53 pm on Nov 12, 2012 (gmt 0)

it's been just over a year since this started.
most of the sites i've looked at are now in the 30%+ range and this tells me about 1/3 of the general search public are logged in.
in some cases the percentage is significantly higher.
haven't seen 50% yet...

How does this work in wmt?

GA depends on the HTTP_REFERER Request header to get keyword information.
GWT can get that information before the HTTP Request is sent.