[Integrations] Integrate with direct selling platforms [Shopify, WooCommerce, Lemonsqueezy, PayHip, etc]

Two reasons for these integrations:

1. After a reader makes a purchase, if they aren’t a subscriber, they would be given the option to become a newseltter subscriber

2. If they are already a subscriber, they could be given a tag / added to a segment showing that they have made a direct purchase and which books they own already.

Either way, this would allow for something like automations to remind the readers to review / rate the book they purchased and make later recommendations for books they should purchase (ex: they bought book 1 in a series, start them in an automation to remind them to buy book 2 in a month).