“Price-fixing would pertain if the defendants (the advertisers) were in the same industry as the plaintiff (X.) Obviously they are not.”
No, dummy, price-fixing is a crime against the buyer, which is X, so they do have standing.
You really do not understand law at all, do you?
“No, dummy, price-fixing is a crime against the buyer, which is X, so they do have standing.”
I might be a dummy, but even I can understand that in the case at hand X is the SELLER of advertising, not a buyer. You seem confused.