App stores only take a non-majority share of the revenue. They also provide the hardware platform, which is not easily replicated. Elsevier, on the other hand,

App stores only take a non-majority share of the revenue. They also provide the hardware platform, which is not easily replicated. Elsevier, on the other hand, takes ALL the profit, and does not have a difficult to replicate position on a hardware platform. The only reason people continue to use them is inertia.