You're asserting that's not how they work, but you're also asserting they're illegally subsidizing their search and maps business with... the revenue they generate from selling ads space on their search and maps businesses.

I'll leave it as an exercise to the lurkers to decide who is probably right.

> you're also asserting they're illegally subsidizing their search and maps business with... the revenue they generate from selling ads space on their search and maps businesses.

Yes, that is how these things tend to work! Seriously, read some books on antitrust, you have no idea what you are talking about. Tim Wu is a good starting point.

A majority of Googles revenue comes from running ads on their own sites. Their third party ad network is a small part of their revenue, so the correct direction is to say that Google is subsidising its third party ad network via their first party ad business.

The effect of antitrust would then be that Google separates the ad service for its own services and third party services, which would force their third party ad service to become more expensive since it can no longer rely so heavily on the draw of all the Google properties.

> they're illegally subsidizing their search and maps business with... [their ads business]

I suspect this is what what @arrosenberg is getting at. If the Search (and maps) business is considered separate from the ads business (Search runs at a massive loss) and it's provided for free because they can subsidize it with the revenue from their ad business, then it's an anti-competetive advantage they have from a monopolistic position that their advertising business has.

Anyway, personally I have no clue how that "works" in practice, but that seems to be the perspective.