The commissions are usually minimal, if not zero. By using the Web, DSPPs are painlessly easy. As for companies, they like the plans, too. The shareholders usually are long-term. What's more, the paperwork is less.
Companies also have a better idea of who their shareholders are.
Well, probably lots of advertising. So don't be surprised if you here more about this over the next year. HP makes money by revenue sharing. The service will be free. By allowing users to do e-commerce.