For anyone playing it: is there any real-money attribute to the game? That seriously kills e.g. Shadow Cities for me, and will probably kill qonqr as well. For Shadow Cities for example, it's not necessary, but it is extremely important for owning locations, which progressively increases in cost (some > 500 'potions', which is roughly equivalent to $30 [1]), or you spend many many hours earning small numbers of them. Yeah, it helps hosting costs, but it ruins the game.
Google doesn't seem to plan on making money from the game directly. The leading theories are that either they're trying to build momentum for Android with a high-profile exclusive title, or they're using data from the game to populate some geolocation database.
Either way, I expect the game to be completely free for the foreseeable future.
My guess is that they have made this into a fun way to get us to send them maps data. We are giving them route data in places that street-view cars cannot access. Players can also submit new portals with geotagged photos, which could help maps/street view/Field Trip/places. Indoor mapping of public buildings might benefit as well. They might also be able to use XM (energy orbs placed around town) to lure players to areas that need mapping info.
[1]: http://shadowcities.wikia.com/wiki/Potions