WhatsApp marketing: when it works and when it becomes an intrusion

WhatsApp has open rates email can only dream of, and that is exactly why it is easy to burn. An unwanted message in an email inbox is annoying. The same message on WhatsApp, between family and work, is an intrusion, and the reaction is faster: the block.

The channel works very well, but under strict rules. They are worth knowing before the first send, not after.

The rules you cannot get around

Consent genuinely matters. It is not a bureaucratic formality: without opt-in you cannot write first, and the channel itself stops you. The clean way to collect it is to ask where the customer already has a reason to give it, at the order, and say plainly what they will receive.

Starting a conversation requires approved messages. If you write first, the message has to take a form approved in advance. You cannot improvise the text of a promotion. That changes how you work: campaigns get designed ahead of time.

There is a window after the customer replies. When the customer writes to you, a period opens in which you can answer freely. After that, you are back to approved messages. It is why customer service on WhatsApp is cheap and campaigns are not.

You pay per conversation, not per message, and the category matters. Meta separates marketing, utility and authentication, with different rates by category and by destination country. A shipping notice and a promotion do not cost the same, and that should shape what you send.

What works, and what gets you blocked

The practical rule is single: on WhatsApp, what works is what the customer would have wanted anyway.

It works to say the order has shipped, with the link to follow it. To answer a question they asked. To tell them the product they waited for is back. To confirm an appointment. These messages resolve a wait: nobody experiences them as advertising, even when they lead to a purchase.

It gets you blocked to send the weekly promotion to everybody, to open with "Hi! Have you seen our new collection?", and to send anything on a Sunday evening. The channel is personal: treat it like a newsletter and it reads as an intrusion even when the offer is good.

The number that matters is not the open rate

Open rates on WhatsApp are high for everybody, so they do not separate a good campaign from a bad one. Two other numbers are useful.

How many block or opt out. That is the real cost of a wrong send, and it does not come back: a contact lost on WhatsApp is lost on a channel where other people actually read you.

How many conversations start, meaning how many people reply rather than simply read. On this channel a reply is the signal that the message was relevant, and it is also the moment you can genuinely sell, because the window opens.

Why it has to see the store

An automated WhatsApp message saying "your order is on its way" without knowing which order, or offering a product that is out of stock, does more harm than silence, because it lands on a channel where the customer expects a real answer.

And when the customer replies, whoever reads has to see what the person answering on the site sees: order history, availability, shipping terms. Otherwise you have two channels giving two different answers to the same question, which is worse than having one.

Frequently asked questions

Can I use the number I already use with customers?

Generally yes, and in coexistence mode the phone app stays active while messages sync both ways. It is the least disruptive way to start, because you are not asking anyone to change number or stop using what they use.

What does answering in chat cost?

Rates are set by Meta and vary by conversation category and destination country, so there is no single price to quote: you see them plainly in your Meta account. What is useful to know is the structure: service conversations cost less than marketing ones.

Can I send the same campaign I send by email?

Technically in part, practically it is the most common mistake. Email tolerates frequency, WhatsApp does not. A prudent rule: on WhatsApp send only what a person would be glad to receive even if they were not buying anything.

How often can I write?

Less often than you will want to. There is no single correct frequency, but the signal to watch is the block rate: if it rises after a send, you have already passed the limit for that audience, and next time does not recover it.

Do I need it if I already do email marketing?

They do different jobs. Email carries long content and recurring campaigns. WhatsApp carries what is urgent or personal: shipping, availability, answers. Using them for the same thing wastes the second and irritates whoever receives it.