Your customer data is yours. Nobody else can see your data unless you give them your login or they crack your password.
So you should keep your password strong and secure. Otherwise it will get cracked by a bot somewhere along the line, and then your customer's names and contact information and piano information will be available to some scumbag somewhere. Use a unique strong password, and change it or contact me immediately if it is ever compromised.
As administrator, I can see summary information about users.
Here's my information, for example:
And this data will just be "active" statistics
(active in some timeframe, probably).
This summary information is between you and me for billing
purposes, when we get around to talking about billing, and will never be
given to or discussed with anyone else.
This site does not have ads or use cookies (beyond the session IDs required to implement a login). Facebook and Google know nothing about us, beyond what their bots are able to pic up publicly, and they'll never have any sort of login, so that won't be much.