"Ignore search, ignore Facebook and Twitter, those are first party"
You're not getting the point: extended network sites is not an isolated product. It exists as a part of a large sub-segment (online ads) which part of an even larger market (ads).
You can take a single sub-sub-segment and call it a monopoly. Its doesn't matter if Coke had 95% of the colas market (it does in several countries), it isn't a monopoly, because it competes with thousands of other drinks.
And you can't just look at market share, you need to look at prices. CPMs are falling dramatically across the board, which is completely incompatible with a monopoly.
There is the economical definition of a monopoly, and then there's the layman definition, which means whatever you want to mean.
You're not getting the point: extended network sites is not an isolated product. It exists as a part of a large sub-segment (online ads) which part of an even larger market (ads).
You can take a single sub-sub-segment and call it a monopoly. Its doesn't matter if Coke had 95% of the colas market (it does in several countries), it isn't a monopoly, because it competes with thousands of other drinks.
And you can't just look at market share, you need to look at prices. CPMs are falling dramatically across the board, which is completely incompatible with a monopoly.
There is the economical definition of a monopoly, and then there's the layman definition, which means whatever you want to mean.