Mozilla has rolled out directory tiles, the company’s advertising experiment for its browser’s new tab page, to the Firefox Nightly channel. We installed the latest browser build to give the sponsored ads a test drive. When you first launch Firefox, a message on the new tab page informs you of the following: what tiles are, a promise that the feature abides by the Mozilla Privacy Policy, and a reminder that you can turn tiles off completely and choose to have a blank new tab page. It’s quite a lot to take in all at once.