Being transparent.
WHAT IT SHOULD COVER
What data you collect Why What you do with it Who else receives it How long you keep it What rights people have How to contact you about it
WHAT IT MUST BE
Accurate to what you actually do.
WHAT NOT TO DO
Copy one from another business.
That describes their practices, not yours.
WHERE TO PUT IT
Linked from every page
At the point data is collected: forms, checkout, signup
WHAT TO MENTION SPECIFICALLY
Analytics Payment processing Any service that receives customer data Marketing communications
THE THIRD-PARTY POINT
Services you use receive data. Say so.
WHAT TO REVIEW
Annually, and whenever you add a service or change what you collect.
THE COMMON FAILURE
A notice written at launch and never updated, while three new services were added.
WHAT TO TAKE ADVICE ON
The wording, if you hold substantial or sensitive data.