Paywall
A paywall is a method of restricting access to content via a paid subscription. Beginning in the mid-2010s, newspapers started implementing paywalls on their websites as a way to increase revenue after years of decline in paid print readership and advertising revenue. In academics, research papers are often subject to a paywall and are available via academic libraries that subscribe.
E-commerce payment system
PaymentWall, an e-commerce solutions providing company launched in 2010, offers a wide range of online payment methods that its clients can integrate on their website the seller integrates it on the website such that you will need use it to perform payment.