Network Effects and Platforms
Why some products become more valuable as more people use them, how platforms that connect two groups set their prices, why these markets tend toward concentration, what weakens network effects, the economics of growing a platform, and the questions an investor should ask.
The short version
A product has network effects when each new user makes it more valuable to the others. They can be direct, as with a messaging service, or indirect, as with a marketplace whose buyers attract sellers and whose sellers attract buyers. Platforms that connect two groups often charge one side little or nothing and earn their money from the other, as newspapers did by giving papers away to attract advertisers. US antitrust agencies note that network effects can create a tendency toward concentration, which makes the leaders valuable and newcomers' lives hard. But network effects can be weakened by users on several platforms at once, by crowding, and by the same dynamic running in reverse.
By the end of this lesson, you'll be able to
- Distinguish direct from indirect network effects and explain why they can make markets concentrated
- Explain how two-sided platforms set prices and why one side is often subsidized
- Identify what weakens network effects and the questions to ask about a platform business
Why this matters
For most products, your enjoyment doesn't depend on how many other people own one. For some, it's almost everything. A phone network with one subscriber is useless; a marketplace with no sellers attracts no buyers. When value grows with the number of users, the economics change: early growth matters more than early profit, markets can tip toward one or two winners, and the winners can be very hard to dislodge. Competitive Advantages listed network effects among the main sources of a lasting edge. This lesson looks at how they work and where they stop.
Two kinds of network effect
US antitrust agencies, in their 2023 merger guidelines, describe Network effects. When each additional user makes a product more valuable to other users. Direct network effects come from users on the same side; indirect ones from users on another side of a platform. Glossary as arising when participants add to a platform's value for other participants, and distinguish two kinds.1
- Direct network effects come from users on the same side. Every new member of a messaging service is someone the existing members can reach.
- Indirect network effects come from users on the other side. More buyers make a marketplace more attractive to sellers, and more sellers make it more attractive to buyers.
| Users | Possible pairs: users × (users − 1) ÷ 2 |
|---|---|
| 10 | 45 |
| 100 | 4,950 |
| 1,000 | 499,500 |
Ten times the users means about a hundred times the possible connections. Most pairs never actually connect, so value doesn't grow nearly that fast, but it shows why a network that's ahead can pull further ahead.
Platforms with two sides
A platform connects groups that benefit from each other. Jean Tirole, who received the 2014 economics prize, worked with Jean-Charles Rochet on these platform markets. The Academy's summary of his work gave examples including newspapers, which link readers and advertisers, credit and debit cards, search engines, and social media.2
The central insight is that the price charged to each side matters, not just the total. The Academy's summary uses newspapers to show it: giving papers away can be a way of attracting readers, and so advertisers, who cover the losses on production and distribution.2
| Pricing | Buyers | Sellers | Sales through the platform | Platform revenue |
|---|---|---|---|---|
| Buyers pay $50 a year, sellers pay 5% of sales | 200,000 | 4,000 | $100 million | $10 million + $5 million = $15 million |
| Buyers free, sellers pay 8% of sales | 1,000,000 | 9,000 | $400 million | $32 million |
Making the platform free for buyers draws five times as many, which draws more sellers and four times the sales. Sellers pay a higher rate but are better off: they keep 92% of $400 million in sales instead of 95% of $100 million. Charging the side that values the other side more can beat charging both.
The rest of this lesson is for members
Still to come in this lesson: Why platform markets concentrate, What weakens network effects, The economics of building one, Questions to ask about a platform, the key takeaways, and 2 quiz questions with explanations.
Membership opens every lesson in the curriculum, the capstone projects, the interactive tools, and the members-only channels in the Hyperion Entities Discord. The first lesson of every module stays free.
Go deeper
- Competitive AdvantagesPart 3: Understanding Businesses
- Competition and Market StructureEconomics for Investors (depth track)
- Pricing PowerEconomics for Investors (depth track)
- Game Theory and Strategic RivalsEconomics for Investors (depth track)
Notes and sources
- U.S. Department of Justice and Federal Trade Commission. Merger Guidelines (December 18, 2023). Checked 2026-10-14. Back to text
- The Royal Swedish Academy of Sciences, via NobelPrize.org. Popular information: The Prize in Economic Sciences 2014 (Jean Tirole). Checked 2026-10-14. Back to text