According to the article, "There will be “Lupin” pillows and Netflix-branded boxer shorts. There will be caps, necklaces, charms and hoodies, all of it for sale at Netflix.shop, a site that goes live on Thursday, when the world’s biggest streaming company plants a flag in the territory of e-commerce."
Orange is the New Black.
Money Heist. (That's Casas de Papel if you're outside of North America.)
The list goes on, and on...
Netflix certainly doesn't have a shortage of fan-loved "Netflix Original" intellectual property to monetize on a shopping site.
And the reason they would want to do so likely has little to do with the amount of money they might make on the sale of those physical goods; even the Netflix executive responsible for this initiative implied the money generated from the boutique shop was not expected to match the amount Netflix makes through its deals with store chains and fashion brands, saying, "Practically speaking, the revenue will come more from those partners around the world in terms of sheer footprint and number of locations and magnitude.”
But if fans purchase branded merchandise to support a show they love, that's free advertising for the show... and that drives interest, subscriptions, and revenue for the streaming giant. As a general rule, when you can get your customers to pay YOU to promote your wares, you should almost certainly do it.