How MLS makes money for its owners

I'm sure you've heard that Major League Soccer struggles to make a profit. We’ve been told that, outside a handful of really successful teams like the LA Galaxy and the Seattle Sounders, most of the league is in the black. We’ve heard the TV revenue isn't large enough and the kit and stadium sponsorships are just good enough to keep the teams going. Indeed, here's an excerpt from the Wall Street Journal from earlier this year that says exactly that:

But, here's there's a weird flip side to this: MLS keeps adding teams. And each time it does, the fee for one of those expansion teams goes up. Ten years ago, Toronto FC came into the league for a fee of $10 million. Now, we are talking about a…