To be fair, with Reader the thought probably was "we will aggregate online content created by others and will add ads to the result. Then profit!" This was replaced with "we will aggregate social content, the add lots of ads. Then profit!"

The thought with Express might go like this: "By pushing the envelope on buying things online, more people will buy thing online than offline, expanding the e-commerce universe. This would translate into higher advertising fees. Then profit."

In other words, they believe that expanding e-commerce will be more profitable than helping two dozen power users consume mostly as free content easier.