Ask a brand what their email programme looks like and you will usually hear about the newsletter: how often it goes out, who writes it, what went in the last one. Ask about the automated flows and the answer is often that there is an abandoned cart email somewhere, set up when the store launched.
The economics are not close
A campaign is a fixed amount of work for a single send. A flow is a fixed amount of work that runs for every customer who triggers it, indefinitely. One is a treadmill, the other compounds. If you have limited hours, they should go to the flows first, every time.
The flows that matter, roughly in order
Welcome. The highest engagement moment you will ever get with a subscriber. Not one email but a short series that sets expectations, tells the story and makes one clear offer.
Cart and checkout abandonment. The obvious one, usually implemented badly: a single reminder an hour later with a discount attached. Better is a sequence that first removes friction, then addresses hesitation, and only then discounts, if at all.
Browse abandonment. Lower intent, higher volume. Often overlooked, frequently profitable.
Post purchase. Shipping updates are transactional. The sequence around them is marketing: setup guidance, care instructions, and the review request timed for after the product has actually arrived and been used.
Replenishment. If your product runs out, the reminder should arrive slightly before it does. The timing is worth more than the copy.
Win back. Cheap to build, unglamorous, and consistently one of the better performers per hour invested.
Then, and only then, campaigns
Once the flows are live and reported separately, the campaign calendar has a job: launches, seasonal moments, genuine news. Not filling space because it is Thursday.
Report them apart
Keep flow revenue and campaign revenue in separate columns. Blended, they hide which half of the programme is doing the work, and that is exactly the number you need when deciding where the next hour goes.