Upcado enables marketers to make use of Messenger marketing. It's similar to email marketing but 3-4x more effective.
With Upcado you can gather subscribers by creating a list and beautiful opt-in widgets. Once you've gathered subscribers you can send marketing campaigns on Facebook Messenger.
I know the team behind Upcado and they are extremely smart, so expect more great things to come along in this product. I've seen demos and tried the product on a staging website, and it is just slick.
This has been a really good way to engage with our users and increase our traffic. I recommend giving it a try