How Do We Verify Course Reviews?

A student who submits a verified review must submit the course that she purchased, the date when she made the purchase, and the e-mail that she used for the purchase.
Beat The GMAT only sends the e-mail, the course and the purchase date to the test prep company. Beat The GMAT does not, however, show the GMAT Company the student's review nor reveal whether the review is positive or negative.
The test prep company confirms that the email, course and purchase date match a real student purchase that was made in their system. The company only gets these three pieces of info and never previews the review before publication.
Beat The GMAT receives confirmation from test prep company and publishes the GMAT course review, assigning a 'Verified Real Student' badge right on the review to indicate that it's indeed a real person sharing her opinion about the course.