One way could be creating an organic Facebook campaign and leading potential customers to a quiz or landing page with the end goal of extracting their email.
From there, you can create an automated email flow selling the product or lead them to join a free Facebook group with the intent of selling them your product.
Or with FB ads, you can just create a PPC campaign leading to a killer product page.
Definitely many other methods but those are two that seem to work best. Let me know if you need help executing any of these