How do I define an ideal customer for a two-sided marketplace where I have to pick two of them?
The short answer
In a marketplace you have two ICPs, but they are not equal partners: pick the harder side to attract as your anchor and define it precisely first. Usually supply is scarcer or pickier, so nail the ideal supplier profile, then define the demand side that specifically wants what that supply offers. Trying to define both broadly at once gives you a thin, unmatched marketplace, so start narrow enough that a supplier and a buyer can actually find each other in one city or one category. Treat the constrained side as the one that shapes everything, and refine from your earliest real matches.
Go deeper, your way
3 hand-picked resources, 3 link-checked. Pick how you want to dig in.
✍️ Essay
✓ Link checkedFreeIntermediate
Why we picked it
For a two-sided marketplace, the first real decision is which side to define and win first, and this essay makes the case plainly: figure out which side is harder to get, because that side is usually the more valuable one, and once you have it the other side gets 2 to 10 times easier. It then walks through concrete ways to seed that harder side without the other side existing yet, so it is a starting point for the pick-two problem rather than abstract theory. NFX has studied more marketplace network-effect businesses than almost anyone, which is why this is the canonical reference founders keep returning to.
From
NFXby James CurrierLong read (about 25 minutes)
Identify the constrained (harder to acquire) side first, and define your ideal customer there, because that side sets the pace for the whole marketplace.
You can build standalone value for one side before the other exists (for example a tool suppliers use whether or not buyers are present) so you are not stuck waiting for both.
There are many concrete seeding levers (subsidies, geographic or category constraints, manual matching), so pick the two or three that fit your niche instead of trying all of them.
Why we picked it
Once you accept that you have to define two customers, you need a deeper model of how the two sides pull on each other, and this is the book that laid the academic and practical groundwork for exactly that. Parker and Van Alstyne effectively founded the theory of two-sided networks, and Choudary translates it into practical platform design, so you get both the why and the how of balancing producer and consumer profiles. Read it after the shorter pieces, when you want the full framework rather than a quick tactic.
From
W. W. Nortonby Geoffrey G. Parker, Marshall W. Van Alstyne, Sangeet Paul ChoudaryBook (about 350 pages)
A platform serves distinct producer and consumer roles, and you have to design a clear profile and value proposition for each rather than treating them as one market.
The two sides create value for each other through network effects, so a decision about one side (pricing, curation, quality) directly reshapes who your ideal customer on the other side is.
Governance and quality control on the harder side are what keep a marketplace liquid as it scales, not just raw growth.
Why we picked it
This is the most concrete answer to which of your two customers to define first, built from interviews with 17 major marketplaces (Airbnb, Uber, Etsy, DoorDash and more) rather than one founder's opinion. The finding is blunt: about 80 percent of successful marketplaces poured their early effort into the constrained side, usually supply, and built liquidity in one narrow niche before expanding. It is a practical playbook you can map onto your own marketplace this week.
Most successful marketplaces defined and won the constrained side first (usually supply), then let demand follow, so start by naming your ideal customer on that side.
Early liquidity comes from going deliberately narrow (one city, one category) and getting it genuinely working before you widen the definition of who you serve.
The number of levers the biggest marketplaces used to grow that first side was small (a median of two), so focus beats spreading effort across both sides at once.
