How do I prove to a client that Instagram brings them leads?

Keep a record of every conversation that asks about buying or booking, with the post that started it, and once a month ask the client which of those people became customers. Then report it plainly: "23 people asked to book, 6 became customers, and this reel started 7 of the conversations."

Analytics won't do this for you, because most Instagram leads for service businesses are conversations, not website visits.

The record needs four columns: who, what they asked, which post started it (and how you know), and the outcome. Fill it in as conversations arrive, not at report time.

The monthly question to the client is the step most agencies skip and the one that makes it proof. The client knows which people became customers. Asking turns your lead count into confirmed customers, and over a few months gives you their real close rate.

Put this at the top of the report, before reach and followers. It's the sentence a business owner can repeat to a partner or an accountant.

The full method is in How Agencies Prove Instagram Brings In Leads (When Google Analytics Can’t See Them).