You will see this on the Property Profile Page where Market Appraisal usually is. If this is a completed property with the buyers details entered, first you will search for the property, click on the completed status button and where you would normally change your status you will see a button that reads View Potential property.
Clicking this button will bring you to the Potential Property Profile.
When a property has Potential instead of Market Appraisal, this means that the property has been entered in any other way than a Market Appraisal or is a completed Market Appraisal, and you have entered in the new potential vendor's information.
Other examples of this are the property was an instant valuation or the property was uploaded manually using a CSV.
On the Potential properties that come from completions, you can see the Final Fee Earned and the Final Sales Price, by clicking the Potential tab below the property details, then clicking Completion Info.