Robin Dunbar discovered something that changed how we understand relationships.
Your brain can only maintain so many connections at different levels of closeness. About 5 loved ones. 15 good friends. 50 close friends. 150 meaningful contacts.
That's it. Cognitive limits. Fixed by biology.
But here's what most people miss… the flip side of that research that nobody talks about.
There's no limit to how many people can have you in their 150.
A successful professional might sit inside the meaningful contacts circle of 500 people. Some might be there for 2,000. That's where real leverage lives.
Not in how many people you know, but in how many people consider you indispensable.
So the question becomes: how do you get there?
It Starts in the First Month
Dunbar's research found something else: you've got about a month after meeting someone to establish where you fit in their mental hierarchy.
Not consciously. They're not rating you on a spreadsheet. But subconsciously, they're asking: How valuable is this person to me?
After about a month, that assessment solidifies. Wherever you land, that's pretty much where you stay.
When you meet someone new in a professional context, you're starting somewhere in the 500–1,500 range. They barely know you. Your goal in that first month is to get inside the 150. The meaningful contacts circle.
Because once you're there, you're there for life.
I Watched Someone Blow It in Real Time
He'd just met someone perfect at a conference. Great fit, genuine interest, natural chemistry. The kind of conversation where you both keep talking past when you were supposed to leave.
He did everything right during the event. Asked great questions. Listened more than he talked. Offered one specific way he could help, right there in person.
Then he went back to his hotel room and ruined it.
He sent one comprehensive email. Everything he'd promised to follow up on, all in one message. Seven bulleted items. Links. Attachments. A closing paragraph about staying in touch.
Thorough. Professional. Well-written.
And it completely killed the momentum.
I know because he asked me why the person never responded.
What Went Wrong
Here's the thing about beginnings: they matter more than anything else that follows.
Researchers call it the primacy effect. Studied for decades across hundreds of experiments. The conclusion is consistent: how something starts determines how it continues.
One email doesn't get you into someone's 150. It uses up all your reasons to stay in touch, and then you drift.
What the science actually shows: frequency of contact matters more than depth of contact when building new relationships.
The mere exposure effect is one of the most replicated findings in psychology: the more someone sees your name or thinks about you, the more they like you. Not one deep interaction. Many small ones.
The Campaign of Helpfulness
Here's how this actually works.
Say you meet someone at a conference. Great conversation. They mention they're trying to scale their business. They're looking for strategic investors, production capabilities, and maybe some operational support. You're in investment banking. This is your world.
What NOT to do: Go back to your hotel room and send one email listing everything. Three investor intros, a market report, a case study, a personal note about their product. All in one message.
What TO do:
While you're still at the event, in the hallway, in your Uber, or on your way out, talk into your phone.
Leave yourself a voice note. Brainstorm every single way you could add value to this person. You might come up with eight or ten things: investor introductions, a market analysis, a founder story, an article on scaling, a photo of your kids with their product.
Then pick the single strongest one from their perspective. Not what's easiest for you. What they'd value most.
Send one short email… 50 words or less, fits on one phone screen:
"Really enjoyed our conversation today. I'm going to introduce you to two strategic investors who specifically look for companies at your stage. Look for a couple emails from me in the next few days connecting you. Happy to prep you beforehand if helpful."
That's it. One thing. High value. Clear next step.
Response rate? Near 100%.
Then execute. And three days later, send the next thing. A week after that, another. You're orchestrating 6–12 touches over about a month, not robotically, but authentically, based on how they're responding.
What This Creates
After a month of this, here's what they're thinking:
"I can't believe I just met this person. They've added more value in four weeks than advisors I've worked with for a year."
That's the feeling you're creating. That's what gets you into their inner 150.
This Doesn't Scale to Everyone
One important caveat: you can't do this for every person you meet. It's too much.
This is for your most important new relationships. The people who could genuinely become meaningful long-term connections. For everyone else, standard follow-up is fine.
But for those high-priority relationships? This approach changes everything.
The Simple Next Step
Think about someone you met recently. Someone who matters.
Brainstorm 8–10 ways you could add value to them over the next month.
Don't send one email with all ten things.
Pick the strongest one. Send it today. Schedule the next one for three days from now.
One month from now, they'll remember you. They'll value you. They'll want to keep you close.
Because you showed up. Consistently. Helpfully. Without asking for anything in return.
That's the reverse Dunbar number in action. No limit to how many people can have you in their 150.
It starts with how you handle the first month.