The second is the realisation that players will happily pay real money for virtual goods.
These can be upgrades, costumes or weapons for their in-game characters,
or (more cynically) a lottery-style “loot box” whose contents are unknown in advance, but might prove valuable enough to resell to other players.
Since the marginal cost of creating virtual items is zero, they are very profitable for developers.
That has given rise to a “freemium” business model, of which Tencent was a pioneer, whereby games are given away cheaply or free but players are constantly nagged to spend money on in-game items.
All this has been supercharged by smartphones, which mean people can keep playing—and paying—at all hours of the day.
The result is an unhealthy loop.
Firms strive to keep players hooked, because the more time they spend in a game, the more money they will spend on baubles within it.
Whizzy data analytics let developers tweak their products to do just that, using psychological tricks and nudges familiar from social-networking sites and the gambling industry.
All this can be extremely lucrative.
Sensor Tower, an analysis firm, reckons that “Candy Crush Saga”, a popular game in the West, made $930m last year.
The keenest gamers, known as “whales” (a term coined by casinos to describe high-rolling customers), can spend thousands of dollars a year.
Tencent is trying to placate the Chinese government.
It is expanding its age-verification scheme and limiting screen time for children.
Its counterparts in other countries should take note.
This newspaper does not generally believe governments should tell adults how to spend their money.
But the industry could do more to protect children and addicts from its increasingly sophisticated products.
It is in its own long-term interests to do so.
Video games now rival the film industry for clout.
Gaming is thought to be worth around $140bn annually worldwide, and is growing at 13% a year.
But society’s attitude towards technology is hardening.
In a world of fake news and hyper-targeted advertising, voters and politicians have awoken to the danger that devices and data may be manipulating people in harmful ways.
A little voluntary forbearance now could save a lot of regulatory pain later.
1.marginal cost 边际成本（经济学专有名词）：边际成本是指厂商每增加一单位产量所增加的成本 。因为固定成本几乎沉没，理论上边际成本可以使企业无损失的继续运转 。
2.strive to 努力
He strives hard to keep himself very fit.
3.tweak something 稍稍改进(如系统或设计)
He expects the system to get even better as the engineers tweak its performance.
4.placate someone 安抚
He smiled, and made a gesture intended to placate me.
5.in the interests of 为了…的利益
a call for all businessmen to work together in the interests of national stability.