Cory Doctorow explains it. First you provide good value to customers to build your business and destroy competition (even losing money if necessary). Then, you

Cory Doctorow explains it. First you provide good value to customers to build your business and destroy competition (even losing money if necessary). Then, you provide good value to partners (e.g. vendors) at your customers' expense to get them locked in. Then in the final stage, you start extracting the value from those partners so that value flows to neither them, nor the end customers.