Make hair styles unlockable like Finishers
Permanent Finishers are sold in the gem store. Account wide hair can be too. Anet would most likely make more money.
This would not work. There is nothing preventing players from creating a character and unlocking one hairstyle for the account, then deleting the character. Create a new character in the same slot, unlocking another hairstyle, and delete again.
Repeat until all hairstyles are unlocked without cost.
People COULD do the repeat thing, but then they would be missing the fact that not necessarily all hair styles are available from character creation. I don’t know if there are any kit-only hairstyles yet, but there are definitely hair colors. If they treated hairstyles more like dye that had a starting set and then had others that could be unlocked later, this could work really well.
Fun on someone else’s schedule is not fun
This would not work. There is nothing preventing players from creating a character and unlocking one hairstyle for the account, then deleting the character. Create a new character in the same slot, unlocking another hairstyle, and delete again.
Repeat until all hairstyles are unlocked without cost.
This is for new hairstyles.