Coopt is a 3rd party app that allows customers to unlock coupons by sharing your store on Facebook. To begin, sign up for a Coopt account, set the amount you wish to offer customers for sharing your store, and Coopt Campaigns will generate a link that you can paste:
in any of your Omnisend emails (it works with both Campaigns and Automated emails).
When the link is clicked and your store is shared, Coopt will verify the post and release the coupon code to the customer. You can see it in action in the video below.