Network effect

Evidence and consequences

While the diversity of sources is in decline, there is a countervailing force of continually increasing functionality with new services, products and applications — such as music streaming services (Spotify), file sharing programs (Dropbox) and messaging platforms (Messenger, WhatsApp and Snapchat). Another major finding was the dramatic increase in the infant mortality rate of websites, with the dominant players in each functional niche, once established, guarding their turf more staunchly than ever.

On the other hand, a growing network effect does not always bring a proportional increase in returns. Whether additional users bring more value depends on the commoditization of supply, the type of incremental user and the nature of substitutes.^[15] For example, social networks can hit an inflection point, after which additional users do not bring more value. This could be attributed to the fact that as more people join the network, its users are less willing to share personal content and the site becomes more focused on news and public content.^[15]

Critical mass

In the early phases of a network technology, incentives to adopt the new technology are low. After a certain number of people have adopted the technology, network effects become significant enough that adoption becomes a dominant strategy. This point is called critical mass. At the critical mass point, the value obtained from the good or service is greater than or equal to the price paid for the good or service.^[17]

When a product reaches critical mass, network effects will drive subsequent growth until a stable balance is reached.^[18] Therefore, a key business concern must then be how to attract users prior to reaching critical mass. Critical quality is closely related to consumer expectations, which will be affected by price and quality of products or services, the company's reputation and the growth path of the network.^[2] Thus, one way is to rely on extrinsic motivation, such as a payment, a fee waiver, or a request for friends to sign up.^[19] A more natural strategy is to build a system that has enough value without network effects, at least to early adopters. Then, as the number of users increases, the system becomes even more valuable and is able to attract a wider user base.^[20]

Limits to growth

Network growth is generally not infinite, and tends to plateau when it reaches market saturation (all customers have already joined) or diminishing returns render the cost of acquiring the remaining customers prohibitive.

Networks can also stop growing or collapse if they do not have enough capacity to handle growth. For example, an overloaded phone network that has so many customers that it becomes congested, leading to busy signals, the inability to get a dial tone, and poor customer support. This creates a risk that customers will defect to a rival network because of the inadequate capacity of the existing system. After this point, each additional user decreases the value obtained by every other user.

Peer-to-peer (P2P) systems are networks designed to distribute load among their user pool. This theoretically allows P2P networks to scale indefinitely. The P2P based telephony service Skype benefited from this effect and its growth was limited primarily by market saturation.^[21]

Market tipping

Network effects give rise to the potential outcome of market tipping, defined as "the tendency of one system to pull away from its rivals in popularity once it has gained an initial edge".^[22] Tipping results in a market in which only one good or service dominates and competition is stifled, and can result in a monopoly. This is because network effects tend to incentivise users to coordinate their adoption of a single product. Therefore, tipping can result in a natural form of market concentration in markets that display network effects.^[23] However, the presence of network effects does not necessarily imply that a market will tip; the following additional conditions must be met:

1. The utility derived by users from network effects must exceed the utility they derive from differentiation
2. Users must have high costs of multihoming (i.e. adopting more than one competing networks)
3. Users must have high switching costs

If any of these three conditions are not satisfied, the market may fail to tip and multiple products with significant market shares may coexist.^[5] One such example is the U.S. instant messaging market, which remained an oligopoly despite significant network effects. This can be attributed to the low multi-homing and switching costs faced by users.

Market tipping does not imply permanent success in a given market. Competition can be reintroduced into the market due to shocks such as the development of new technologies. Additionally, if the price is raised above customers' willingness to pay, this may reverse market tipping.^[5]

Multiple equilibria and expectations

Network effects often result in multiple potential market equilibrium outcomes. The key determinant in which equilibrium will manifest is the expectations of the market participants, which are self-fulfilling.^[2] Because users are incentivised to coordinate their adoption, users will tend to adopt the product that they expect to draw the largest number of users. These expectations may be shaped by path dependence, such as a perceived first-mover advantage, which can result in lock-in. The most commonly cited example of path dependence is the QWERTY keyboard, which owes its ubiquity to its establishment of an early lead in the keyboard layout industry and high switching costs, rather than any inherent advantage over competitors. Other key influences of adoption expectations can be reputational (e.g. a firm that has previously produced high-quality products may be favoured over a new firm).^[24]

Markets with network effects may result in inefficient equilibrium outcomes. With simultaneous adoption, users may fail to coordinate towards a single agreed-upon product, resulting in splintering among different networks, or may coordinate to lock-in to a different product than the one that is best for them.^[2]

Telephone

Network effects are the incremental benefit gained by each user for each new user that joins a network.^[43] An example of a direct network effect is the telephone. Originally, when only a small number of people owned a telephone, the value it provided was minimal. Not only did other people need to own a telephone for it to be useful, but it also had to be connected to the network through the user's home. As technology advanced, it became more affordable for people to own a telephone. This created more value and utility due to the increase in users. Eventually, increased usage through exponential growth led to the telephone being used by almost every household, adding more value to the network for all users. Without the network effect and technological advances, the telephone would have nowhere near the amount of value or utility it does today.

Financial exchanges

Transactions in the financial field may feature a network effect. As the number of sellers and buyers in the exchange who have symmetric information increases, liquidity increases, and transaction costs decrease.^{[44][failed verification]} This then attracts a larger number of buyers and sellers to the exchange.

The network advantage of financial exchanges is apparent in the difficulty that startup exchanges have in dislodging a dominant exchange. For example, the Chicago Board of Trade has retained overwhelming dominance of trading in US Treasury bond futures despite the startup of Eurex US trading of identical futures contracts. Similarly, the Chicago Mercantile Exchange has maintained dominance in trading of Eurobond interest rate futures despite a challenge from Euronext.Liffe.

Cryptocurrencies and blockchains

Cryptocurrencies such as Bitcoin and smart contract blockchains such as Ethereum also exhibit network effects.

Smart contract blockchains can produce network effects through the social network of individuals that uses a blockchain for securing its transactions. Public infrastructure networks such as Ethereum and others can facilitate entities that do not explicitly trust one another to collaborate in meaningful ways, incentivizing growth in the network. However, as of 2019, such networks grow more slowly due to missing particular requirements such as privacy and scalability.^[45]

Software

Widely used computer software benefits from powerful network effects. The software-purchase characteristic is that it is easily influenced by the opinions of others, so the customer base of the software is the key to realizing a positive network effect. Although customers' motivation for choosing software is related to the product itself, media interaction and word-of-mouth recommendations from purchased customers can still increase the possibility of software being applied to other customers who have not purchased it, thereby resulting in network effects.^[46]

In 2007 Apple released the iPhone followed by the app store. Most iPhone apps rely heavily on the existence of strong network effects. This enables the software to grow in popularity very quickly and spread to a large user base with very limited marketing needed. The Freemium business model has evolved to take advantage of these network effects by releasing a free version that will not limit the adoption or any users and then charge for premium features as the primary source of revenue. Furthermore, some software companies will launch free trial versions during the trial period to attract buyers and reduce their uncertainty. The duration of free time is related to the network effect. The more positive feedback the company receives, the shorter the free trial time will be.^[47]

Software companies (for example, Adobe or Autodesk) often give significant discounts to students.^[48] By doing so, they intentionally stimulate the network effect - as more students learn to use a particular piece of software, it becomes more viable for companies and employers to use it as well. And the more employers require a given skill, the higher the benefit that employees will receive from learning it. This creates a self-reinforcing cycle, further strengthening the network effect.

Web sites

Many web sites benefit from a network effect. One example is web marketplaces and exchanges. For example, eBay would not be a particularly useful site if auctions were not competitive. As the number of users grows on eBay, auctions grow more competitive, pushing up the prices of bids on items. This makes it more worthwhile to sell on eBay and brings more sellers onto eBay, which, in turn, drives prices down again due to increased supply. Increased supply brings even more buyers to eBay. Essentially, as the number of users of eBay grows, prices fall and supply increases, and more and more people find the site to be useful.

Network effects were used as justification in business models by some of the dot-com companies in the late 1990s. These firms operated under the belief that when a new market comes into being that contains strong network effects, firms should care more about growing their market share than about becoming profitable. The justification was that market share would determine which firm could set technical and marketing standards and giving these companies a first-mover advantage.^[49]

An example here could be social networking websites; the more people register on a social networking website, the more effect it has on its registrants.^[50]

Google uses the network effect in its advertising business with its Google AdSense service. AdSense places ads on many small sites, such as blogs, using Google technology to determine which ads are relevant to which blogs. Thus, the service appears to aim to serve as an exchange (or ad network) for matching many advertisers with many small sites. In general, the more blogs AdSense can reach, the more advertisers it will attract, making it the most attractive option for more blogs.

By contrast, the value of a news site is primarily proportional to the quality of the articles, not to the number of other people using the site. Similarly, the first generation of search engines experienced little network effect, as the value of the site was based on the value of the search results. This allowed Google to win users away from Yahoo! without much trouble, once users believed that Google's search results were superior. Some commentators mistook the value of the Yahoo! brand (which does increase as more people know of it) for a network effect protecting its advertising business.

Rail gauge

There are strong network effects in the initial choice of rail gauge, and in gauge conversion decisions. Even when placing isolated rails not connected to any other lines, track layers usually choose a standard rail gauge so they can use off-the-shelf rolling stock. Although a few manufacturers make rolling stock that can adjust to different rail gauges, most manufacturers make rolling stock that only works with one of the standard rail gauges. This even applies to urban rail systems where historically tramways and, to a lesser extent, metros would come in a wide array of different gauges; nowadays, virtually all new networks are built to a handful of gauges and overwhelmingly standard gauge.

Credit cards

For credit cards that are now widely used, large-scale applications on the market are closely related to network effects. Credit cards, as one of the currency payment methods in the current economy,^[51] which was originated in 1949. Early research on the circulation of credit cards at the retail level found that credit card interest rates were not affected by macroeconomic interest rates. Later, credit cards gradually entered the network level due to changes in policy priorities and became a popular trend in payment in the 1980s.^[49] Different levels of credit cards separately benefit from two types of network effects. The application of credit cards is related to external network effects, because once established as a payment method, more people use credit cards. As each additional person uses the same credit card, the value to the rest of the people who use the credit card will increase.^[26]

The credit card system at the network level can be seen as a two-sided market. The number of cardholders attracts merchants to accept credit cards as a payment method. An increasing number of merchants can also attract more new cardholders. In other words, the use of credit cards has increased significantly among merchants, which leads to increased value. This can conversely increase the cardholder's credit card value and the number of users. Moreover, credit card services also display a network effect between merchant discounts and credit accessibility. When credit accessibility increases, which can improve sales, merchants are willing to be charged more by credit card issuers.^[52]

Visa has become a leader in the electronic payment industry through the network effect of credit cards as its competitive advantage. Until 2016, Visa's credit card market share had risen from a quarter to as much as half in four years. The popularity and convenience of Visa in the electronic payment market lead more people and merchants to choose to use Visa, which increases the value of Visa.^[53]