This moves the problem of defining a market to defining a submarket.
Please don't interpret this as my being facetious. In the days of good and services being sold to consumers, we had metrics to measure this. The government measured and the courts incorporated said metrics into antitrust law. Those measures don't work well in the digital era. These cases are about proposing new measures and getting them to stick.
Mind bogglingly, the FTC didn't propose such a metric. That's why its complaint was dismissed. I'm curious to see what they propose, if anything.
A fair point, because Walmart, Target, CVS, Costco, etc all vertically integrate and sell their own (often whitelabeled) products on their shelves, alongside other companies' goods.
In that case, the core product (to other businesses) is shelf space.
So is there a monopoly on shelf space control?
Walmart is huge. But Target's pretty big too (~10% their size by revenue). And they've got bigger competitors in grocery.
But in the Facebook case, where else are you going to buy eyeball time? The closest thing to the scale of Facebook ad space would be if Google put ads on the launcher of Android.
