What is the PieSync definition of a contact?
Your billing is based on the number of contacts (kept in sync), but defines 'a contact'?
A contact is simply any one record that PieSync can be synced. Contacts come in many different shapes and sizes (leads, companies, users, ...). As long as it is a record that stores contact information, we consider it to be a contact record.
this could be a contact record, a company record, or a lead record. They have one thing in common though, they all store contact information about a single individual or entity, so we just call them contacts
In other words. If you keep 1000 contacts, 500 company record and 500 leads in sync, then your billng will be based on 2000 contacts.