Seems to me much of the conversion policy problem is very similar to why Microsoft has been able to retain its huge advantage in the software business (aside from the monopolistic practices):

It's called "installed base" in the computer world. The pound/gallon/mile system (by whatever name you choose to call it) has a huge "installed base", both in the minds of the users and in books, instruments, signage, prices, and who knows what else.

Dave Oesterreich