Not able to review product on Microsoft AppSource

[MLollen]

Is there a requirement for reviewing products on AppSource. When I login and check I am able to review a certain product, but for another product I do not. We are trying to send out requests for reviewing to customers but want to make sure we are meeting requirements in order to do so. 

Is there a requirement customer has to meet in order to review a product?

[#2]

In my experience, if a customer has clicked through Appsource for your solution (Get It Now button), they should be able to leave a review.
-JL