Sponsored message API has officially moved to the page level today. Lots of confusion. Lots of questions. This is the quick and dirty explanation or what is happening and what to expect from here. 

Resources mentioned: 

Should you apply? https://chatbotslife.com/should-you-apply-for-subscription-messenging-for-your-messenger-bot-4c207bb6f981

List of tags: https://developers.facebook.com/docs/messenger-platform/send-messages/message-tags#

YouTube video - How to create a custom audience: https://www.youtube.com/watch?v=HWY7Lwhy4nI

YouTube video - How to create a sponsored Message: https://www.youtube.com/watch?v=qbwXABUlzVw