How to get a free sample from Sephora?

Excuse me, could you possibly elaborate on the steps one might take to acquire a complimentary sample from Sephora? I've heard whispers of such an opportunity, but I'm uncertain of the exact protocol. Do I need to make a purchase in order to qualify, or is there a specific service I must inquire about? I'm eager to try out some new products, and the idea of a free sample sounds incredibly appealing. Would you kindly guide me through the process?