Sounds sensible, but how does one ensure that the "lots of consumer options" part holds? There seem to be quite a few sectors with winner-take-all dynamics (e.g

Sounds sensible, but how does one ensure that the "lots of consumer options" part holds? There seem to be quite a few sectors with winner-take-all dynamics (e.g. social networking), and quite a few other sectors that under many conditions tend toward oligopoly or monopoly (e.g. insurance, banking, credit history reporting).