来源：哈佛商学院在线
本文较简单，内容偏商业，适合英语二考生。
What Are Network Effects?
The term network effect refers to any situation in which the value of a product, service, or platform depends on the number of buyers, sellers, or users who leverage it. Typically, the greater the number of buyers, sellers, or users, the greater the network effect—and the greater the value created by the offering.
“In other words, the willingness to pay, for a buyer, increases as the number of buyers or sellers for the business grows,” says Harvard Business School Professor Bharat Anand.
Examples of Network Effects
Many of today’s most popular companies and startups are heavily influenced by network effects, such as:
E-Commerce: eBay, Etsy, Amazon
Rideshare: Uber
Delivery: Uber Eats
Social Media: Facebook, Twitter, Instagram, LinkedIn, Snapchat, Pinterest
What each of these companies has in common is that the value they provide to customers increases as they acquire more users. Etsy and eBay offer vastly more value to users if one million, instead of 100, sellers use their platforms. Uber provides greater convenience and reliability to riders when more drivers join its platform. When it comes to social media sites, users find the channels more interesting and varied as more people sign up.
Direct and Indirect Network Effects
Not all network effects are the same. They’re often broken into two different types: direct and indirect.
Direct network effects occur when the value of a product, service, or platform increases simply because the number of users increases, causing the network itself to grow.
Social media platforms primarily benefit from direct network effects because the service's value grows as a direct result of attracting more users.
Indirect network effects, on the other hand, occur when a platform or service depends on two or more user groups, such as producers and consumers, buyers and sellers, or users and developers. As more people from one group join the platform, the other group receives a greater value amount. This is best illustrated by the e-commerce and ridesharing examples noted above.
另一方面，当一个平台或服务依赖于两个或两个以上的用户群体时，如生产者和消费者、购买者和销售者、用户和开发者，就会产生间接的网络效应。当一个群体中有更多的人加入这个平台时，另一个群体获得了更大的价值。上面提到的电子商务和共享出行的例子最能说明这一点。
Why Are Network Effects Important to Understand?
The underlying principles of network effects imply that the business, website, or platform with the highest market share will be more successful in the long run. This means that its market share is likely to grow more substantially. For this reason, markets in which network effects play a major role are often referred to as winner-takes-all markets.
网络效应的基本原理意味着，从长远来看，拥有最高市场份额的企业、网站或平台将更成功。这意味着其市场份额可能会有更大幅度的增长。因此，网络效应起主要作用的市场通常被称为赢者通吃的市场。
“Companies that can leverage network effects often experience rapid rates of growth,” Anand says. “Not just that: Once you’re ahead, you tend to stay ahead. Your demand keeps growing even faster as you get bigger.”
Network Effects and Pricing
To maximize profit margin, businesses typically price their products as high as possible without exceeding their customers’ willingness to pay. But when a market is subject to network effects, the driving concern isn’t so much profit as it is market share—especially early on.
为了最大限度地提高利润率，企业通常会在不超出客户支付意愿的情况下，尽可能地提高产品价格。但当一个市场受到网络效应的影响时，驱动因素与其说是利润，不如说是市场份额，尤其是在早期。
This is because future customers’ willingness to pay depends on the number of existing users. By growing your market share early, you increase your ability to raise prices at a later date, once you’ve taken advantage of network effects and driven adoption of your offering as much as possible. For this reason, many companies price their products low early on or give them away for free.
这是因为未来客户的付费意愿取决于现有用户的数量。一旦你充分利用了网络效应，并尽可能地推动人们接受你的产品，那么通过尽早增加市场份额，你就能够在以后提高价格。出于这个原因，许多公司在早期将产品定价较低或免费赠送。
The emergence of Facebook as a social media giant is an excellent example of this premise in practice. When Facebook launched in 2004, it was a free social media platform. By virtue of being free, the platform became more popular, capturing greater market share and eventually displacing Myspace, its primary competitor at the time. It wasn’t until 2007 that Facebook introduced ads in an effort to monetize its user base, and it wasn’t until 2013 that the company noticeably increased those efforts.
社交媒体巨头Facebook的出现就是一个很好的例子。当Facebook在2004年成立时，它还是一个免费的社交媒体平台。由于免费，该平台变得更受欢迎，获得了更大的市场份额，最终取代了Myspace，后者是其当时的主要竞争对手。直到2007年，Facebook才引入广告，试图通过用户群实现盈利，直到2013年，该公司才显著努力从广告方面盈利。