I can think of a couple of things that branding achieves:

• Establishing a history of good relationships with customers.
• Being a costly signal of trustworthiness.
• Tapping into tribal instincts (hello Apple).

The first two functions are a low-tech way to build reputation. Reputation networks could efficiently replace branding and strongly diminish the economies of scale. There are still economies of scale (the more customers, the stronger the confidence in your brand) but the scale power coefficient is likely much smaller.

Reputation networks even allow “brands” to bootstrap. A company could place bets on the average rating it receives from a large pool of reviews. This allows individual consumers to hedge their asymmetric risk without allowing them to game the outcome.