You could expand the question to say why do abc, disney, and espn all include go.com in their url? Obviously they all share the same ownership. Although I think there would be better ways to promote cross brand pollination.
There's an interesting history there. I'm not sure why they haven't changed to just use their own domains, given how much of a failure the go.com portal concept was.
There's an interesting history there. I'm not sure why they haven't changed to just use their own domains, given how much of a failure the go.com portal concept was.