Which of the following is NOT true about online marketplaces?

In many ways, online marketplaces are the perfect business model. Since they facilitate transactions between independent suppliers and customers rather than take possession of and responsibility for the products or services in question, they have inherently low cost structures and fat gross margins. They are highly defensible once established, owing to network effects.

Presumably, a doctor could even quantitatively measure how much you suffer. Knowing the circuitry of the brain and how it relates to brain disorders, psychiatrists might also objectively monitor treatment and give scientists new targets for treatment. When weak connections between specific brain regions are seen, there might be some new way to manipulate and strengthen them. "We don’t just want to understand the brain," says Seung. "We want to change it. "