Marketplaces

The umbrella concept in Kyle’s notes for two-sided / network businesses that match buyers and sellers. It is the parent node for two adjacent threads he captured on June 18, 2026: B2B Marketplaces and SaaS + Marketplace. All three pages point at the same saved source — Casey Winters’ caseyaccidental.com essay on the SaaS + marketplace model — which is the link Kyle was working through when he split the topic into these related stubs. The marketplace pages function as a small cluster: the general concept here, the B2B vertical-specific variant, and the hybrid model that layers software on top of a marketplace.

Context: A marketplace is a platform that connects two or more sides of a transaction (e.g. buyers and sellers, supply and demand) and typically monetizes via take rate, subscription, or both; the “SaaS + marketplace” pattern adds software tooling to deepen engagement and reduce disintermediation.

Where this appears

• B2B Marketplaces — the business-to-business variant; shares the Casey Winters source link.
• SaaS + Marketplace — the hybrid software-plus-marketplace model from the same captured source.

From Roam

• How to Kickstart and Scale a Marketplace Business by Lenny Rachitsky
  • **Phase 1: Crack the chicken-and-egg problem **🐣
    • Part 1: Constrain the marketplace
      • “Everyone’s always looking for the hack - what’s the channel that will unlock something big? But every time we looked for a reason we weren’t growing, it always came back to the basics –– selection, delivery quality, pricing. That’s it. Always come back to first principles. Whenever we made a mistake, we forgot this.” Micah Moreau (DoorDash, VP of Growth) First Principles
      • Definition of a Marketplaces: A marketplace business is one that (1) connects demand (i.e. people who want a thing) with (2) supply (i.e. people who have that thing), and (3) leads to a financial transaction. These businesses do not generally own any supply, do not provide products or services directly, and (eventually) handle the money being exchanged. Simply put, their job is to provide a platform where the supply and demand efficiently find each other and transact successfully.
      • Why are marketplaces great businesses?
        • Network effects: The more users you get, the more useful/cheap your product becomes, the more users you get (e.g. Lyft/Uber vs. taxis)
        • Barrier to entry: Once they have a strong network effect, it becomes increasingly difficult to enter or replicate the marketplace (e.g. Airbnb vs. hotels)
        • Efficiency: No inventory means cheaper to operate (e.g. Airbnb vs. hotels)
        • Scalability: No inventory means easier to scale (e.g. Rover vs. dog hotels)
        • Flexibility:  No inventory means easier to pivot (e.g. Uber Black -> Uber X)
      • However, when your marketplace is just getting started, and you have neither supply nor demand, it’s challenging to get the Flywheel going. You must convince one side of the marketplace to commit before the other side.
      • The first major learning that emerged from this research is that, with the exception of one company, every single marketplace that I interviewed constrained their initial marketplace to more quickly get to critical mass.
        • Find quote about not necessarily wanting huge initial TAM because you want to find something you can be the best at the world at #Benchmark Find the Quote
      • The research points to two ways to constrain a marketplace: (1) by geography, and (2) by category. If the offering requires supply and demand to be in the same physical location, the constraint is always geographical (e.g. a limited set of markets). Otherwise, it’s category-based (e.g. handmade goods).
      • “We created a playbook for opening up a new market, which got set by the Launcher team (led by Austin Geidt). The first thing they would do when they launched market is to figure out supply. The goal was to get over 30 drivers, shooting for ETA of less than 15 minutes.” Andrew Chen Uber
      • “From the beginning, we had only three categories of things you could sell: vintage items, craft supplies, and handmade items.” Etsy, Dan McKinley
    • Part 2: Decide which side of the marketplace to concentrate on
    • Part 3: Drive initial supply
    • Part 4: Drive initial demand
  • Phase 2: Scale your marketplace 📈
    • Part 1: Determine if you are supply or demand constrained
    • Part 2: Scale growth levers
    • Part 3: Maintain quality
    • Part 4: What would you have done differently if you did it again
  • Phase 3: Evolve your marketplace 🐛
    • Part 1: Move to a managed marketplace
    • Part 2: Add new business lines