Most people have received an introduction they did not ask for. A message lands with their name next to a stranger's, a line saying "you two should talk", and an unspoken expectation that they will reply. Saying no now feels rude to two people at once. Many reply out of politeness, take a call they did not want, and become a little more wary of the person who introduced them.
The double opt-in introduction fixes that with one extra step: ask first. It helps to know where the idea comes from, how it compares with the usual single opt-in approach, how to run one step by step and what to say when someone declines. Asking first matters even more in a WhatsApp community, where a phone number is often the first thing to be shared.
Where the double opt-in introduction comes from
The term was popularised by the investor Fred Wilson in a post on his blog AVC on 3 November 2009. His rule is short: when introducing two people who don't know each other, ask each of them to opt in to the introduction before making it. He wrote that he received many introductions a day and felt pressure to take meetings he did not want, which left less time for the people he did want to meet.
Wilson admitted that asking first creates more work for the person in the middle, and still called it good form. Auren Hoffman's 2010 essay on email introductions makes the same point as one of its rules: contact both people beforehand, make the case for the meeting and check that they are open to it.
The idea spread well beyond investors. Recruiters, community organisers and business networks use it for the same reason. An introduction asks for someone's time and attention, so it should start with their agreement, not end with it.
Single opt-in vs double opt-in introduction
In a single opt-in introduction, only the person asking has agreed. The person being introduced finds out when the message arrives. In a double opt-in introduction, both have agreed before either receives the other's details.
| Single opt-in | Double opt-in | |
|---|---|---|
| Who agrees first | Only the person asking | Both people, separately and privately |
| When details are shared | Straight away, in the introduction | Only after both have said yes |
| Saying no | Awkward: both people see the reply or the silence | Easy: the person in the middle hears it alone |
| Effort for the introducer | One message | Two or three short messages |
| What the other person learns about a decline | Often obvious | Nothing, unless the decliner wants to say |
| Typical result | Polite replies that go nowhere, or no reply | Fewer introductions, but more that lead to a real conversation |
The extra effort is real but small. In return, every introduction that goes ahead has two willing people in it, and the person in the middle keeps the trust of both.
How to run a double opt-in introduction
These steps assume you know both people and one of them has asked for help. The order matters: ask the person who will give their time first, because they have more to lose from an unwanted introduction.
- 1Get the need in writing from the person asking: what they want, by when and where. Ask whether you may mention their name when you approach someone, or describe the need without it.
- 2Message the person who could help, privately. Describe the need, say why you thought of them, and make declining easy: "No problem at all if the timing is wrong."
- 3Wait for a clear yes. Silence is not a yes. If there is no reply after a few days, treat it as a no and move on.
- 4Go back to the person asking. Tell them who agreed and check that they still want the introduction and are happy for you to share their contact details.
- 5Send the introduction to both in a new private chat or email: a line on each person, why you are connecting them and a suggested next step.
- 6Step out of the conversation and follow up once, a week or two later, to ask whether it helped.
For the opt-in question itself, a simple version works: "A member is looking for help with a commercial lease in Mohali and I thought of you. Would you be open to an introduction? Completely fine to say no." The free introduction message generator writes both the opt-in question and the introduction for you.
What to say when someone declines
A double opt-in only works if no is a real option. That means the person who declines should not have to explain, and the person asking should not find out who said no.
To the person who declined, a short thank-you is enough. Do not ask why, and do not try again with the same request next week. If they offer a reason, such as being too busy this month, note it so you do not ask them again too soon.
To the person asking, say that the first person you approached could not help this time and that you are trying someone else. Do not name who declined. If nobody suitable agrees, say so honestly. A clear "I could not find anyone for this" is more useful than a slow fade, and it tells you which needs your network cannot meet yet.
Why double opt-in matters more in WhatsApp groups
In email, an unwanted introduction costs time. In a WhatsApp community it can also cost privacy, because the contact detail being shared is a personal phone number. Once someone has a number, they can message or call at any time, add it to other groups, or pass it on. A number cannot be taken back once it is shared.
Groups make single opt-in the default without anyone deciding it. A member posts a need, someone tags a name, and the tagged member is now publicly connected to the request with their number visible to everyone. WhatsApp's own community safety guide warns admins that @mentioning a member in an announcement group exposes that contact's phone number to the entire community, and its safety advice tells members to avoid sharing personal information in groups.
Asking privately before anything is shared fixes both problems. It keeps the request out of the group, and it means a number moves only when its owner has agreed to that particular introduction.
Running double opt-in at scale
Doing this by hand is fine for a few introductions a month. Past that, the organiser becomes a switchboard, and the opt-in step is the first thing to be dropped when they are busy.
Milvao builds the double opt-in into every request in a WhatsApp community. The member asking confirms a short brief of their request, then separately chooses whether their number may be shared for that request. The member being asked receives the brief, without the asker's name, number or exact words, and has 48 hours to tap Accept or Decline. Contact details go to both people only after both have said yes, and Milvao checks both consents again right before sending. A decline is never shown to the person asking, and Milvao moves on to the next best fit.
The full model, including what each side sees at every step, is on Who sees what, and the Help Center covers the details under Introductions and contact sharing.
Sources
- Fred Wilson, AVC: The double opt-in introduction (3 November 2009) (checked 5 November 2026)
- Auren Hoffman: Art of the email introduction (19 May 2010) (checked 5 November 2026)
- WhatsApp Communities: Building a safe community (checked 5 November 2026)
Milvao publishes this guide and makes a product for WhatsApp communities, so we have a stake in the topic. Facts about WhatsApp and other services come from the sources listed, on the dates shown, and can change. Corrections are welcome through our contact page.