WhatsApp lead magnets: send the brochure on a keyword and capture the opt-in in the same chat

Aslam Patel sells sarees and dress material wholesale from a two-floor shop in Surat’s textile market, with twelve staff and retailers across Gujarat and Maharashtra (an invented business, for the examples). His catalogue is a PDF that changes every Friday. For two years it went out by hand: a retailer messaged “catalogue bhejo”, a salesman found the latest file on his phone, sent it, and forgot to ask anything. Aslam had thousands of chats and no list.

A WhatsApp lead magnet fixes the order of events. The retailer sends one word, CATALOGUE, from a link in an Instagram bio or a QR code on an exhibition stall. The file comes back in seconds. The same automation asks whether they want Friday’s catalogue every week, and records the answer. Only then does a person join the chat.

How the keyword arrives

Through a click-to-chat link with the keyword pre-filled, placed wherever the customer already is.

WhatsApp’s click-to-chat page gives the format: https://wa.me/ plus your number in international format, then ?text= and the URL-encoded message. With <number> standing for the shop’s WhatsApp Business number, Aslam’s link is https://wa.me/<number>?text=CATALOGUE. Tapping it opens WhatsApp with CATALOGUE in the text box; the customer sends it. That is the enrolment.

Use a different source word on each placement, so the first message says where the customer came from.

Where the link lives	Pre-filled text	What you learn
Instagram bio and a link sticker on a Story	CATALOGUE INSTA	Which reel or Story brought them
QR code on the exhibition stall and the shop counter	CATALOGUE STALL	Walk-in versus online
Website product pages	CATALOGUE WEB	Which page they were on
A click-to-WhatsApp ad	The ad’s own pre-filled text	Meta attaches the ad to the chat
Printed on the invoice and the parcel	CATALOGUE BILL	Repeat buyers asking again

Our guides to QR codes for offline leads and adding WhatsApp to a website have the placements and the encoding, and the click-to-WhatsApp ads piece explains why an ad chat is the one source where even templates are free for up to 7 days.

WhatsApp keyword auto reply: what sends the brochure

On the WhatsApp Business Platform, an automation that reads the first message and replies with a document message. The free WhatsApp Business app can’t do this.

The app’s greeting message goes out once to a new chat and its away message on a schedule; neither reads the text, and quick replies are shortcuts a person taps (our auto-reply guide lists what else they can’t do). A keyword reply needs the Platform through a provider, where a journey matches the first message against CATALOGUE and sends the file.

The file itself is a document message. Meta’s page, updated 21 May 2026, lists the supported types as PDF, Word, Excel, PowerPoint and plain text, each up to 100 MB, with an optional filename so the phone shows the right icon and a caption of up to 1,024 characters. Our media size guide has every type and the rules for images and video.

The cap is not the constraint. A retailer in Nashik on a patchy connection doesn’t want 40 MB of photographs to see whether you have cotton prints this week. Aslam’s rule is a PDF under 3 MB, named patel-textiles-catalogue-17-oct.pdf so the retailer can find it again on Friday, and a caption that names the week and the shop.

What the automatic brochure costs

About ₹115 before GST per thousand requests, once the free allowance is used.

The customer’s keyword opens a 24-hour customer service window, and everything you send inside it that isn’t a template is a service message. Since 1 October 2026 Meta gives each business number 1,000 free service messages a month and charges ₹0.115 per delivered message to an Indian number after that, before GST; reactions stay free. Our October cost guide has the table.

For 1,000 keyword requests in a month on one number: 1,000 document replies plus 1,000 opt-in questions is 2,000 service messages. The first 1,000 are free and the next 1,000 cost 1,000 × ₹0.115 = ₹115. If Aslam’s team also answers questions in those chats, each answer is another ₹0.115 after the allowance. The figures are illustrative arithmetic at Meta’s listed rates, not a benchmark.

The opt-in, in the same chat

Sending the brochure is not permission to send anything else. Ask in the same chat, with a button, and keep the answer.

Meta’s opt-in page, updated 16 June 2026, lists three requirements: you must “clearly state that a person is opting in to receive communication from the business”, “clearly state the business’s name”, and comply with applicable law. It leaves the method to you. A keyword request meets none of the three on its own; “CATALOGUE” says nothing about future messages.

So the automation sends a second message with two reply buttons, thirty seconds after the file:

HW Hemant Wagh talking to Patel Textiles

1. Hemant Wagh:
   CATALOGUE STALL 4:02 pm
2. Patel Textiles:
   Patel Textiles catalogue, week of 17 October. 142 designs, wholesale rates on the last page. PDF, 2.8 MB. 4:02 pm
3. Patel Textiles:
   Would you like Patel Textiles to send you the new catalogue on WhatsApp every Friday, and occasional stock offers? Reply STOP any time. 4:03 pm
   • Yes, every Friday
   • No, just this one
4. Hemant Wagh:
   Yes, every Friday 4:05 pm
5. Tagged: catalogue · stall · opted in 17 Oct 2026
6. Patel Textiles:
   Done. If you want prices on a particular design, send me its number and I will reply here. 4:05 pm

Our opt-in guide lists what to record: number, date and time, source, the wording shown and what they agreed to. A customer who taps “No, just this one” still gets this week’s file and any answers to questions they ask, and nothing after the window closes.

Meta has its own mechanism for this. In-App Signup, documented on a page updated 3 July 2026, is an opt-in deep link in the form wa.me/<number>/signup/<id>. The customer opens it, sees your signup message on a pre-consent screen (1 to 300 characters), confirms, and receives a confirmation message of up to 300 characters that can carry a promo code. Meta’s exclusion list (the EEA, the UK, Brazil, Japan, South Korea, Nigeria, South Africa and Turkey) doesn’t include India. It needs a published privacy policy URL, and your provider has to build it; ask them.

On Indian law: the Digital Personal Data Protection Rules, 2025 were notified in November 2025, and their consent-notice rules apply from around May 2027, so nothing in them binds your opt-in today. Treat the months until then as preparation: a button tap with a date and the wording beside it is the shape of record those rules will expect. This is general information, not legal advice.

What you may send afterwards

Inside the window, anything. After it, only a template, and the category decides the price and whether you need the opt-in.

What you send after 24 hours	Category Meta will give it	India rate, per delivered message	Needs opt-in
”Your sample order 4471 has shipped”	Utility: specific to a request	₹0.1150	Request itself
Friday’s catalogue with prices and offers	Marketing: promotional content	₹0.8631	Yes
”Did the PDF open? Reply 1 for a smaller file”	Marketing: a nudge to someone who went quiet	₹0.8631	Yes
A reply to a question they asked today	Service, inside the window	1,000 free, then ₹0.1150	No

On the awkward row, Meta’s categorization page says utility templates must be non-promotional and either requested by the user or essential; retargeting messages “are marketing even if requested by users”. A catalogue is promotional content. If a plain “your syllabus is attached, as requested” template is approved as utility, good, but plan at the marketing rate and let Meta surprise you the cheap way.

Two more limits. Marketing templates go only to people who said yes, and WhatsApp caps how many marketing templates a person receives from all businesses combined; the cap is dynamic and Meta publishes no number, though templates delivered inside an open window don’t count toward it. Our piece on error 131049 covers the failed-delivery signal.

A 14-day follow-up, with the arithmetic

Three messages at most to people who said yes, and nothing to people who didn’t.

Day	To whom	Message	Type	Cost per 1,000 requests
0	Everyone who sent the keyword	The file, then the opt-in question	2 service messages	First 1,000 free, then ₹0.115 each
2	Opted in, no reply since	One useful thing: three designs selling fastest this week	Marketing template	300 × ₹0.8631 = ₹258.93
7	All opted in	Friday’s catalogue	Marketing template	400 × ₹0.8631 = ₹345.24
14	All opted in	Next Friday’s catalogue, and a minimum-order offer	Marketing template	400 × ₹0.8631 = ₹345.24

The counts are a worked example, not a forecast: 1,000 requests, 400 who tapped yes, 300 of those who went quiet after the file. On those numbers the month costs ₹115 for the service messages plus 1,100 × ₹0.8631 = ₹949.41 for the templates, about ₹1,064 before GST. The 600 who declined cost nothing after day 0, which is the point of asking. A retailer who replies on day 2 or 7 reopens a window, and your answers are service messages.

Then stop, unless the person writes. The 90-day plan in our WhatsApp marketing strategy picks up from the opted-in list, and the template examples have wording for the day-7 and day-14 sends.

Twelve WhatsApp opt-in campaign ideas, by trade

The best magnet is the thing customers already ask your staff for by hand. Each of these is sent as a document, a list message or a short reply inside the window, and each pairs with the same opt-in question.

Trade	Lead magnet	Keyword	What the opt-in asks for
Textile and garment wholesale	Weekly catalogue PDF	CATALOGUE	New catalogue every Friday
Interiors, modular kitchens	Price list by size	PRICE LIST	Seasonal offers
Resort, clinic, gym	Brochure with facilities and rates	BROCHURE	Off-season rates and new packages
Coaching institute	Syllabus and batch timetable	SYLLABUS	Batch start dates and results
Real estate	Project plan and payment schedule	PLAN	Launch and possession updates
Restaurant, cloud kitchen	Menu with today’s specials	MENU	Weekend specials
Clothing and footwear brand	Size chart with measuring guide	SIZE	New drops and sale dates
CA, tax and compliance firm	Monthly filing-deadline checklist	CHECKLIST	Deadline reminders each month
Solar, loans, insurance	Calculator result from one number	SAVINGS	Follow-up on the quote
Diagnostic lab, nutritionist	Sample report of a package	SAMPLE	Package offers
Salon, tutor, physiotherapist	This week’s open slot list	SLOTS	Weekly slot list
Consultant, software, edtech	Webinar seat and joining link	WEBINAR	Replay and the next session

The calculator one is the odd one out: the customer sends SAVINGS 5 for a 5 kW roof, the journey does the arithmetic and replies with the estimate. The answer is about their house, not your product, which is why people reply to it.

What to measure

Four counts per source, every week: keyword requests, opt-ins, replies after the file, and bookings or orders.

Requests tell you whether the placement works: a stall QR code that produces four requests in three days of an exhibition is a signage problem. Opt-ins over requests tell you whether the question is right; if few say yes, change the wording and the promise (“every Friday” beats “occasional updates”) before you change the magnet. Replies tell you whether the file answered anything, and orders whether to keep paying for follow-ups.

Keep the source word on the contact, not just the chat, so a month later you can see that stall contacts order and Instagram contacts browse. Terms used here, from customer service window to utility template, are in our glossary.

Aslam’s first change was not the automation. It was writing the opt-in question down and agreeing that nobody sends a catalogue without it. Do that this week, by hand if you must, and automate it when the volume says so.