Common attitude to Comscore numbers in the Web industry is yes, their data is off, but they're under-/over-counting everyone more or less equally, so relative positions and growth numbers are generally correct.
With that said, mobile used to be Comscore's Achilles heel, not sure if they're started buying click data from mobile ISPs to rectify that. Gmail is leading US email client, and Gmail Mobile combined with Google Maps might make Google the largest mobile property.
With that said, mobile used to be Comscore's Achilles heel, not sure if they're started buying click data from mobile ISPs to rectify that. Gmail is leading US email client, and Gmail Mobile combined with Google Maps might make Google the largest mobile property.