Network effects can accelerate both growth and concentration

A messaging app offers excellent features, but nobody in your study group uses it. Your classmates join. Suddenly it becomes useful for arranging meetings, because their participation changes what you can do with the same app rather than merely adding to its total user count.

That is a direct network effect. The relevant users matter, since thousands of strangers joining may add little value to a tool you want mainly for contacting a few classmates.

Some effects run through a complementary group

A game console with many players can attract developers. More games can then attract additional players, creating an indirect network effect that reaches each group through participation on another side of the market.

Separate this from production costs. A factory might lower its average cost as output expands, whereas a messaging app can become more useful when friends join even if its cost per user stays unchanged. Both effects can occur together.

Growth can also spoil an experience. Crowding, unwanted messages or competition for attention may offset benefits from additional participants, so an effect that is positive at one network size need not remain positive at every scale.

Examine the new rival's problem

A rival offers a better messaging feature. That may be insufficient to attract a user who would lose contact with friends, especially if moving successfully requires persuading the friends to move as well.

This is a coordination problem. An early lead can expand when new participants make a network more useful, but the existence of that feedback does not prove the market must become a permanent monopoly.

Communities sometimes move together. A rival can also serve a particular group well enough to overcome a small initial network, with product quality, trust and the costs of switching affecting the result.

Check whether users can keep alternatives

A restaurant lists on several delivery apps. This is multihoming. The restaurant can try a rival without abandoning its existing service, while customers with several apps can compare the options for a particular order.

Interoperability lets systems work together. When people on different services can communicate, joining a small service need not cut someone off from an established group, though the available features and safeguards affect the benefit.

Portability does a different job. Exporting a contact list helps someone move information, but it does not ensure those contacts will join the new service or make their messages compatible with it. For a competition question, inspect the actual switching costs and connections between services before deciding how much protection an established network has.

Watch the idea in action

A related lesson from Andreas Munzel / Marketing Analytics Academy. Read the examples above alongside the video.

Open the video on YouTube · Educator lesson and source

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