The list you build slowly outperforms the list you buy instantly, and it is the only one that will not cost you your number.
Why buying a list fails commercially, not just legally
A purchased list has no consent, which breaches both Meta policy and data protection law. Set that aside for a moment and it still fails on its own terms: cold recipients block at a rate that drags the quality rating down within one or two campaigns.
Losing a messaging tier costs you months of warming. A cheap list that costs you the ability to message the customers you do have is not cheap.
Sources that actually produce opt-ins
- A website chat widget with a pre-chat form, which captures the number even if they never send the message
- QR codes on packaging, receipts, table tents and shopfronts
- Click-to-WhatsApp ads, where the click itself starts the conversation
- A separate, unticked consent box at checkout — separate from terms acceptance
- An invitation campaign to existing customers on channels you already have consent for
- Offline capture at counters and events, with the source recorded
What makes the consent valid
Consent has to be free, specific, informed and unambiguous, given by a clear affirmative action, with the purpose stated. A pre-ticked box fails. Consent bundled into general terms fails. "By continuing you agree" fails.
The practical test is whether you could answer, for any single contact: when did they consent, through which channel, and to what. Store the source as a field on the contact and that question takes one lookup.
Incentives, and their trap
Offering something for opting in works, and there is nothing wrong with it. The trap is offering something so valuable that people opt in for the incentive alone and mute you immediately afterwards.
A better incentive is one tied to the value of the channel itself: early access, order updates, a stock alert. Those attract people who want the messages rather than people who want the voucher.
The first message sets the block rate
- Send a welcome message promptly, while the opt-in is still fresh in memory.
- Say what they will receive and roughly how often.
- Say how to stop, in the message, not in a footer nobody reads.
- Deliver the promised incentive immediately if one was offered.
- Do not sell in the first message.