Why Business Development Is a (Very) Long Game - What Dunbar’s Number Tells Us About Building Client Relationships

In professional services, relationships drive everything.

Your ability to win work and retain clients is directly tied to the strength of your network.?

But how long does it take to build a genuine business relationship??

A coffee meeting won’t cut it. A single lunch won’t do it. The reality is trust takes time—and science backs this up.?

Dunbar’s Number & The Time Investment of Relationships?

British anthropologist Robin Dunbar found that our brains can only maintain about 150 meaningful relationships at any given time. Beyond that, connections become weaker.?

But even more interesting is the time it takes to develop a strong relationship:

• 50 hours → Acquaintance
• 90 hours → Friend
• 200+ hours → Close friend or strong bond?

These are huge investments - 50+ hours just to initiate a meaningful connection!

The Professional Services Problem?

Here’s where many professionals struggle:

• We expect too much, too soon from new contacts.
• We confuse a transactional interaction with a real relationship.
• We underestimate how much time we need to put in.

The Business Development Reality?

If you’re looking to build deep, valuable, long-term relationships in business, a significant time investment is required.?

Think about your best clients—how much time did you actually spend with them before you became their trusted advisor??

Business relationships evolve in stages:? ? ? ? ?

Acquaintance Stage

• Light interactions (you meet at events, maybe a coffee meeting).
• No deep trust yet—just the embers of a relationship.

Familiarity Stage

• A few meetings, deeper conversations.
• You start to understand each other and can determine whether you are aligned.

Trust & Value Stage

• Regular discussions, helping without expectation.
• They see you as more than a service provider—you become part of their trusted circle.

Advocate Stage

• They see you as their go-to person.
• They refer others to you.

While new relationships can occasionally lead to immediate opportunities, consider those the exception rather than the norm.

If you want to build real, revenue-generating relationships, you need to commit to the long game.? ? ? ? ?

Be present: Relationships aren’t built through sporadic check-ins. Regularity matters.

Give before you get: Provide value long before a client ever pays you.

Deepen the relationship: Move beyond surface-level chats. Get into their challenges, goals, and business pressures.? ?

Track your investment: If you’ve only put a few hours into a relationship, don’t expect deep trust yet.?

Final Thought?

The next time you expect a quick win from a new contact, ask yourself: Have I really put in the hours??

Chances are, the answer is no.?

Play the long game.