Yeah I agree, it comes down to a few factors:
1. The technician - they need to have prepped the eyelashes correctly, they need to have perfect bonding techniques, they need to have applied eyelash extensions to natural eyelashes of the correct length and placement.
2. The client - they need to have refrained from wearing mascara on the day of the appointment, they need to understand the stringent aftercare procedure: not getting eyelashes wet for at least two hours after application, not to visit steam rooms or saunas regularly, to not have water from the shower jet streaming directly onto the lashes...etc....
I have many regular clients who return every 2-3 weeks for maintenance. I also have a few clients who grumble about the price and only have eyelash extensions applied for special occasions.
As well as providing my client with comprehensive afercare advice, I have a section on my consultation forms which lists the activities they must refrain from doing whilst wearing eyelash extensions, they then sign this form. This usually really drives it home regards what they must and must not do with their eyelash extensions.