What it is
An email platform organised around sequences and tags rather than campaigns. A new client gets tagged, the tag triggers a welcome sequence, and the sequence sends the five emails you would otherwise write by hand every time.
Best for
Automating onboarding. Write the welcome email once, the "here is how check-ins work" email once, the "your first week" email once — then stop writing them.
Watch out for
Pricing scales with list size, including subscribers who never open anything, so prune. And automation makes bad emails arrive reliably — write them properly before you schedule them.