A follow-up needs new information
"Still there?" carries nothing new; it only reminds someone they have not bought. Every follow-up should carry one fact they did not have: a stock change, how to use the product, what happened for a comparable customer. With nothing new to say, say nothing.
Three cadences, chosen from the last reply
Hours for high intent, days for the undecided, weeks for cold. Decide from the timing and content of the last reply rather than from one shared schedule. The same customer belongs in different cadences at different stages.
Plan a route for silence and one for objections
Silence is not refusal, and an objection is not the end. When it goes quiet, offer information from a different angle. When there is an objection, confirm what they are actually worried about before explaining anything. Write both next steps in advance.
After two unanswered messages, change channel or stop.
Write the rhythm down so it can be handed over
A cadence in a document can be reviewed, handed over and run by an AI. One that lives in somebody's habits disappears when they do. Write the rule first, automate second.