That's a great guess, partially because they're indeed involved in antitrust suits for all three of those at the moment! Plus the "attorney-client privelege" ac

That's a great guess, partially because they're indeed involved in antitrust suits for all three of those at the moment! Plus the "attorney-client privelege" action as the metacherry on top. That said, I think they're talking about three monopolies within Display Ads: publisher network, ad exchange, and advertiser network. AKA "sellside", "the auction", and "buyside". I see what you're saying with monetization, but this is slightly different than what you're thinking of: this is "Display Ads", which is indeed a product (or, again, 3+ products) that they sell to others. A name you might know is "AdSense". The whole search part of their business is completely separate, and you're absolutely correct that they're a natural+benign monopoly over Google Search ads, just like Microsoft has a monopoly on Bing Search ads. But, again, this lawsuit is more about the little images and videos you see on blogs, news sites, forums, etc.