Today, Google will have a final chance to prove to a federal judge that its advertising business isn’t a monopoly. The US Department of Justice spent several weeks earlier this year arguing that Google maintains too much control over web advertising and uses that power to lock in customers, leaving little room for competition. The trial wraps up this week. If it loses, Google could have to make sweeping changes to the core of its business.

Even if the tech behemoth emerges from this trial…