The focus should be on making it user friendly and starting with the top end of the currency as the standard unit (bitcoin) and moving down the scale just isn't user friendly.
Setting the standard with 2 decimal places would be inline with most western based currencys which works great. Or if we could go with the smallest unit of currency as the standard which is similar to the yen.
I'd be in favor of microbit (uBTC / 1e-6) for these reasons:
- Solves having to re-denominate the currency again in the future.
- Only two decimal places which is inline with the western currency system making adoption easier.
- Easier to pronounce. "You can buy seventy seven thousand eight hundred and fifty one microbits (77,851 uBTC) for ten dollars" is easier to pronounce than "You can buy zero point zero seven seven eight five one bitcoins (0.077851) for $10"
- The psychological barrier of entry is much lower because you're getting tens of thousands of something instead of one of something or even a fraction of something.
- uBTC is already compatible with every finance based database in existance.
- People will get confused between microbits and millibits as they're both visually and audibly similar.