Countries have their own laws with different requirements per jurisdiction regarding the use of privacy policies. Make sure you are following the legislation relevant to your activities and location.
What type of information do you collect?
How do you collect information?
Why do you collect such personal information?
How do you store, use, share and disclose your site visitors' personal information?
How (and if) do you communicate with your site visitors?
Is your service targeting and collecting information from minors?