Robert_Charlton - 6:52 pm on Sep 22, 2011 (gmt 0)

I wish IP address didn't matter so much, it would be nice and convenient, not to mention cheaper, to simply use one host.

This may in fact be why it matters. Google wants to return sites that have a genuine local presence. As local results become more important, Google needs to make it harder to game them.

Chances are that a combination of factors enter into determining the geo-location of any particular site... inbound links, location-specific content, the nature of the competition, and probably other sites in a given company's portfolio. Hosting location is among these.

I wouldn't be surprised if Google considers availability of good hosting in a given country as one of the signals it looks at when weighing IP location.