Quote from James A.Hart on July 17, 2025, 12:07 am

Before you invest time, money, or energy into launching a product, there’s one quick test you should always do:

Can you list four products that your target customer is already buying?

This is called the 4-product rule, and it’s one of the fastest ways to validate whether your business idea has real potential.

Why the 4-Product Rule Matters

A common mistake new entrepreneurs make is choosing a product idea before they fully understand the customer.

They get excited about a supplement, or a gadget, or a skincare item… but they haven’t asked:

“What else does this person buy?”
“Will this be their only purchase from me?”
“Do I actually understand this market?”

The 4-product rule forces you to think bigger. It’s not just about launching one product — it’s about building a brand that serves one person in multiple ways.

The Rule: List Four Products for One Type of Customer

Here’s how it works.

Pick your target customer. Then, try to list four different products they already buy.

If you can’t list four, that’s a red flag. It likely means:

• You don’t know the customer well enough.
• You’re not truly interested in this market.
• Or the market might be too small to support a brand.

But if you can list four, then you’ve got a foundation. You’re no longer building a one-product hustle — you’re building a business with room to grow.

Real Examples of the 4-Product Rule

Let’s say your customer is a biohacker.
You might list:

• Coffee
• MCT oil
• Protein bars
• Meditation retreat programs

All those products serve the same person. That’s a strong foundation.

Or your target is someone following the paleo diet.
You could list:

• Salad dressings
• Cooking oils
• Frozen paleo meals
• Paleo snack bars

Again — clear buying behavior. Same customer. Multiple needs.

Why This Rule Helps You Focus

Without this rule, you risk building two businesses at once.

For example:

• You start with a skincare product for women…
• Then launch a nootropic for gamers…

Now you’ve got two separate audiences. Two separate marketing strategies. Twice the work.

But when you focus on one person, everything aligns:

• Product development
• Branding
• Messaging
• Email marketing
• Repeat purchases

You create brand loyalty — not just one-time sales.

Final Tip: Don’t Overthink It

You don’t need to reinvent anything. Your job isn’t to create brand-new products.

Instead, look at what already exists — and ask:

• What are people already buying?
• Where are the gaps?
• How can you build a brand that brings these products together for one specific person?

That’s how strong brands are built:
One clear customer. Multiple products. Repeated trust.