An ecosystem is a set of actors that depend on one another for survival and growth. In nature, species occupy niches; they compete, cooperate, and co-evolve. In business, ecosystems are platforms, suppliers, complements, and customers whose fates are linked. The model transfers because the same logic applies: you cannot understand one actor in isolation. Change one part and the rest respond. Remove a keystone and the system can collapse.
Ecosystems have structure. Keystone species — or keystone players — have outsized impact relative to their size. Remove them and the system degrades. Niche players depend on the keystone for distribution, standards, or demand. The health of the whole depends on balance: too much concentration and the system is brittle; too little coordination and it fragments. Strategic insight: map who depends on whom, who captures value, and who could be replaced. Then decide whether you are building a keystone, occupying a niche, or designing the rules of the system.
Tech ecosystems illustrate the transfer. Apple's ecosystem — hardware, OS, App Store, developers, users — is a web of complements. The iPhone is valuable because of the apps; the apps exist because of the installed base. Microsoft's enterprise ecosystem (Windows, Office, Azure, partners) locks in through interdependence. Amazon's marketplace connects sellers, buyers, and logistics. In each case, the winner is not just the best product but the one that orchestrates or dominates the ecosystem. The model warns: competing on product alone in an ecosystem game is a losing move. You must understand and influence the whole.
Section 2
How to See It
Ecosystems show up when value and survival depend on other actors' choices. Look for mutual dependence, shared standards, and players whose exit would damage many others.
Business
You're seeing Ecosystems when a platform's growth depends on third-party developers, and developers depend on the platform's user base. App stores, cloud marketplaces, and API ecosystems all exhibit this. The platform sets rules and takes a cut; complements add value; the system grows or shrinks together.
Technology
You're seeing Ecosystems when a standard (e.g. USB, HTTP, a programming language) enables a network of interoperable products and services. No single firm "owns" the ecosystem, but the firms that shape the standard or dominate key nodes capture disproportionate value. Ecosystems can be open (many contributors) or orchestrated (one or few leaders).
Investing
You're seeing Ecosystems when a company's moat is "we sit at the centre of a network of partners and customers." The risk is ecosystem capture: if one player becomes too dominant or the rules change, niche players suffer. Due diligence should map dependencies and ask who could replace the keystone or rewrite the rules.
Markets
You're seeing Ecosystems when industries organise around a hub — a dominant platform, a critical input, or a bottleneck. Suppliers and complements cluster around the hub. The hub's decisions ripple outward. Market structure is not just supply and demand; it is the topology of who feeds whom.
Section 3
How to Use It
Decision filter
"Before entering a market or building a product, map the ecosystem. Who are the keystones? Who are the niches? Where does value flow? If you are not a keystone, your fate is tied to one. If you are building a keystone, design for the long-term health of the system, not just your slice."
As a founder
Decide your role: keystone, niche, or ecosystem architect. As a keystone, you provide something others cannot replicate — distribution, standards, trust — and you capture value by enabling the system. As a niche player, pick a keystone that is aligned with your growth and not so dominant that it can squeeze you. As architect, you design the rules (APIs, revenue share, governance) so the ecosystem stays healthy and you retain influence. The mistake is building a great product without a plan for the ecosystem you sit in.
As an investor
Assess ecosystem position. Does the company depend on a single platform or partner? What happens if that partner changes terms or builds in-house? Companies that are keystones have structural advantage; companies that are fragile niches in someone else's ecosystem carry hidden risk. Look for businesses that create or control an ecosystem, or that have diversified their ecosystem dependencies.
As a decision-maker
When evaluating partnerships, M&A, or product strategy, map the broader system. Will this move strengthen our position in the ecosystem or make us more dependent? Who benefits when we win? Who is hurt? Ecosystem thinking reveals second-order effects that single-actor analysis misses.
Common misapplication: Calling any set of related players an "ecosystem." The term implies interdependence and co-evolution. A supply chain is not always an ecosystem; a platform with complements is. Reserve the model for systems where actors' success is meaningfully linked and where the structure (keystone, niches, rules) determines outcomes.
Second misapplication: Assuming the keystone is invulnerable. Keystones can be disrupted by new technology, regulation, or a shift in complements. Ecosystems can flip when a niche grows into a new keystone or when the centre of gravity moves. Treat ecosystem position as dynamic.
Jobs built Apple as an orchestrated ecosystem: hardware, OS, App Store, and developers. The iPhone's value depended on apps; apps depended on Apple's distribution and tools. He controlled the keystone and the rules. The result was a closed but highly coherent ecosystem where Apple captured value and users got a curated experience. The strategic lesson: ecosystem design can be deliberate, and the keystone can enforce quality and consistency in exchange for control.
Andreessen has repeatedly framed tech competition as ecosystem competition. Netscape tried to own the browser as a keystone to the early web; Microsoft won by bundling IE with Windows. At a16z, he advises founders to think in terms of ecosystem position — are you the platform, a critical complement, or a replaceable piece? Building "just a product" in an ecosystem-dominated market is a recipe for commoditisation.
Section 6
Visual Explanation
Ecosystems — Keystone at centre; niches depend on it. Value flows through the system. Remove the keystone or break the rules and the structure can collapse.
Section 7
Connected Models
Ecosystems connect to network effects, complements, and system-level strategy. The models below either describe how ecosystems create value (network effects, flywheel), how parts relate (complements, interdependence), or how to analyse system-level impact (externalities, critical mass).
Reinforces
Network Effects
Network effects mean that each additional user or complement increases the value of the system. Ecosystems often exhibit network effects: more developers make the platform more valuable; more users attract more developers. Ecosystem strategy and network-effect strategy are often the same game.
Reinforces
Complements & Substitutes
Complements are products or services that increase the value of yours; substitutes replace you. In an ecosystem, you need to identify who is complement and who is substitute — and who could switch. Keystones often have many complements and few substitutes; niches have one or few keystones and many substitute niches.
Leads-to
[Flywheel](/mental-models/flywheel)
A flywheel is a self-reinforcing loop. Ecosystems can create flywheels: more users → more complements → more value → more users. The ecosystem model helps you see where the flywheel sits and who captures the spin.
Leads-to
Positive & Negative Externalities
Ecosystem actors create spillovers — positive when one player's success helps others, negative when one player's behaviour harms others. Ecosystem health depends on internalising positive externalities (e.g. shared standards) and curbing negative ones (e.g. free-riding, predation).
Section 8
One Key Quote
"Companies need to think about the health of the ecosystem as a whole, not just their own position within it."
— James F. Moore, The Death of [Competition](/mental-models/competition) (1996)
Optimising only your slice can damage the system. Over-extraction from complements, broken rules, or neglect of shared infrastructure can shrink the pie for everyone, including the keystone. Ecosystem leadership requires balancing capture with investment in the whole.
Section 9
Analyst's Take
Faster Than Normal — Editorial View
Map before you move. The biggest strategic errors in platform and partnership strategy come from ignoring ecosystem structure. Who is the keystone? Who depends on whom? Where does value flow? Answer these before committing to a product or partnership.
Choose your role deliberately. Keystone, niche, or architect. Each has different risks and returns. Niche players can be highly profitable but carry dependency risk. Keystones capture value but bear responsibility for system health. Architects set rules but may not control the key assets. Pick the role that fits your assets and appetite.
Ecosystems are dynamic. A niche can become a keystone (e.g. a critical app that the platform cannot afford to lose). A keystone can be disrupted. New entrants can change the topology. Revisit the map as the market evolves.
Health over short-term extraction. Keystones that squeeze complements too hard trigger defection, regulation, or replacement. The best ecosystem players invest in the system — developer tools, standards, trust — and capture value over time rather than maximising take rate today.
Section 10
Summary
Ecosystems are sets of interdependent actors — keystones and niches — whose fates are linked. The model transfers from ecology to business: map who depends on whom, who captures value, and who could be replaced. Strategy is choosing whether to be keystone, niche, or architect and designing for the health of the system, not just your slice.
Foundational business application of ecosystem thinking. Moore introduced the ecosystem metaphor to strategy and described how to lead and adapt within business ecosystems.
Practical treatment of platforms as ecosystem orchestrators. Covers network effects, governance, and the transition from pipeline to platform business models.
Academic framing of ecosystem structure and the risks of ecosystem misalignment. Adner's work on "value blueprints" and ecosystem dependency is directly applicable to strategy.
Multiple articles on ecosystem strategy, platform dynamics, and how incumbents and attackers can use ecosystem thinking.
Reinforces
Interdependence
Interdependence is mutual dependence. Ecosystems are defined by it. The strategic question is whether you are comfortable with your level of dependence and whether you have leverage (e.g. as a critical complement) or are replaceable.
Tension
[Critical Mass](/mental-models/critical-mass)
Ecosystems need critical mass to take off — enough users, enough complements. Before that point, the system may be unstable or unattractive. The tension: getting to critical mass often requires subsidy or openness that can later be hard to reverse or that attracts competitors.
