Yes, NFC (Near Field Communication) tags do work. NFC is a short-range wireless communication technology that allows devices to communicate with each other when they're in close proximity, typically within a few centimeters. NFC tags are small, passive devices that can store and transmit information when brought into contact with an NFC-enabled device, such as a smartphone or tablet.

NFC tags can be programmed with various types of data, such as URLs, text, contact information, or commands. When an NFC-enabled device comes into contact with an NFC tag, it can read the information stored on the tag and perform actions accordingly. For example, tapping an NFC tag embedded in a poster might open a webpage on your smartphone, launch an app, or perform other predefined actions.

NFC technology is commonly used for various applications such as contactless payments, access control, transportation ticketing, and smart advertising. So, yes, NFC tags do work and have a wide range of practical applications.