Twitter launched an in-beta test of its "Buy now" button that allows select users to purchase items directly from tweets without leaving the Twitter platform. The button was tested with partners like Burberry, Eminem, Rihanna, and Pharrell Williams, enabling followers to instantly buy items mentioned in tweets. While most e-commerce sites take a fee per transaction, Twitter will not charge brands or artists for the "Buy Now" feature at this initial stage. The launch is currently small and only available to some US users as Twitter aims to refine the user experience before a wider rollout.