[cromwellian]

AFAIK, Google are not selling advertising in ingress like that, so I think you're making bad assumptions. That doesn't leave out people spamming/gaming the system just like blackhat SEOs try to game Google search. I don't think the Ingress people really have the resources to curate all portal submissions.

It also could be to bootstrap the system, they just points of interest or business entries from Google Map's database. Otherwise, the game would be boring for most people with no portals nearby to play with.

(If you live in the suburbs, sometimes the nearest interesting thing is a Safeway or Quiznos)

[healsdata]

No, they made a deal with ZipCar to advertise in game via portals. And every portal submission is reviewed by hand. The quality of the review varies, but there's a 130 day delay right now.