Well, that's our problem in EU - no unified Cell Network - operators milk their intra-EU traveling customers however they want. There's some progress in EU parliament/commision, but it is so slow it will take 50 years before we get unified market. US has range of other problems with telco market though.
It won't be too long before the value of the ads placed in applications like this will be able to subsidize the entire experience, globally.
Google is in the business of bringing their services TO you, this application being one good example.
But like Google Voice and Voicemail, they are also finding ways to completely reinvent industries without locking you in. You don't have to use Google Voice, but boy it's valuable if you do.
I think at some point not to far from now, we're going to see Google Bandwidth or Google Data, which will offer IP-based wireless services for free while wiping out the concept of roaming.
Google makes money on ads through the usage of online services. The pricing structures in the telcos is frequently designed to make usage expensive/difficult.
Google's going to make it easier, again, by cutting the telcos out the equation almost entirely. Their investments in dark fibre and the future investments they'll make off the back of their ad business makes this quite a linear equation as bandwidth becomes cheaper.
Google is going to become the most feared company in the world . . . feared by business, not by users.
