How can I apply a unique coupon to a group of pre-existing buyers?

You can do this automatically with the AutomateWoo extension: https://woocommerce.com/products/automatewoo/

When a customer purchases item A, it will trigger an email that includes the coupon for item B.

Here’s a case study that is similar to what you are looking to do, but can be tweaked to fit your exact needs.

https://automatewoo.com/docs/examples/cross-sell-workflows/encourage-repeat-purchases-by-showing-your-customers-related-products-in-your-store-include-a-coupon/

Hope this helps!

Hi,
We’ve not heard back from you in a while, so I’m marking this thread as resolved. Hopefully, the above plugin suggestion was helpful.

If you have further questions, please feel free to open a new topic.

Thanks.