Every other tool here answers a question about your numbers. This one answers a different question.
Each entry says when to use it, when to skip it, and what it costs. None of them says what it did for somebody else.
Capture
Turning traffic into a contactable person.
Progressive capture
Ask for one thing, then ask for the rest once they have said yes.
Use it whenYour form asks for more than an address, and you cannot justify each field.Skip it whenYou genuinely cannot act on a lead without the extra fields. Then ask, and say why.Read itWriting the part above the cut
The visible part of a post is the advertisement for the rest.
Use it whenEvery post, and especially one opening with a long sentence.Skip it whenYour post is short enough to show whole. Then there is no cut.Read it
Convert
Turning a contactable person into a first purchase.
The welcome sequence
The only messages that reach every subscriber you will ever have.
Use it whenYou have one welcome email, or none. One is the most common answer.Skip it whenNever. This is the cheapest work on this site.Read itCart recovery
Reaching somebody who already chose the product and then stopped.
Use it whenAnything is abandoned at all, which is everywhere.Skip it whenYou have no way to see an abandoned basket. Fix that first.Read itJudging a send per person, not per send
Your biggest earner is often your worst performer.
Use it whenYou rank sends by total revenue, which is the default everywhere.Skip it whenYour sends all go to similar sized groups. Then the two rankings agree.Read itPutting the specific thing first
Whatever gets cut off was never read, so it was never persuasion.
Use it whenAlways, and especially when your preview text repeats the subject.Skip it whenNever. It costs one minute per send.Read itChecking the HTML, not the preview
A preview renders your mistakes exactly as faithfully as your design.
Use it whenBefore every send, which is the point.Skip it whenYour platform already blocks a send on these. Few do.Read it
Retain
Turning a first purchase into a second.
Replenishment timing
Reminding somebody before they run out, not on a round number.
Use it whenYou sell anything consumable and your reminder is on a round number.Skip it whenYour product does not run out. A reminder then reads as a brand that is not paying attention.Read itSending less to the quiet ones
Mailing your least engaged group less often, to protect everyone else.
Use it whenYou send everything to everybody and your placement has softened.Skip it whenYour list is small and new. There is not enough history to judge anyone on.Read itFinding your frequency ceiling
The point where the people you lose outnumber the people you add.
Use it whenYou are considering sending more, or somebody has asked you to.Skip it whenYou send once a month. The ceiling is not your problem yet.Read it
Expand
Increasing value per customer.
Choosing a channel by profit, not by cost
Text costs more per message. That decides nothing on its own.
Use it whenSomebody has argued that text is too expensive, or that email is free.Skip it whenYou have no consent to text anyone. Get that first, properly.Read itMoving volume into automation
Messages that send themselves usually earn more per send than the ones you schedule.
Use it whenAutomations are a small share of your volume and a large share of your revenue.Skip it whenYour automations already earn less per send than your campaigns. Something else is wrong.Read itAsking for the shape before the task
A model told what to produce first produces it. Told last, it corrects.
Use it whenAny repeated piece of work you hand to a model.Skip it whenA one off question you can correct faster than you can specify.Read it
Reactivate
Bringing back the ones who went quiet.
Fixing authentication before anything else
No amount of better writing helps a message that never arrives.
Use it whenBefore any reactivation work, and before blaming the copy.Skip it whenYou checked it this week and nothing has changed since.Read itTreating a blocklist entry as a symptom
Delisting without finding the cause buys about three weeks.
Use it whenYou are listed anywhere that affects delivery.Skip it whenThe entry is a policy one saying an address should not send directly.Read it