Subscription

The concept of a subscription service can be a total game changer. Customer retention is a standard metric, and with monthly subscription, the customer is automatically charged and another purchase is automatically sent. This is convenient for the customer and a lucrative business model for you.

Dollar Shave Club went from a scrappy startup to a Billion dollar company, using this model, and a single, viral video commercial, that became a meme for other successful companies. Subscriptions can be recurring orders of the same thing, like health supplements, or they can be sample packs, and with opportunities for partnership and more business, by giving people a monthly sampling of different products in your category.

Subscriptions are a little more complicated to put together than some of the other models, but is an opportunity to keep in mind.

You could also consider something like "Patreon" as a combination Subscription and Digital Product.