Twitter has entered the digital ad sphere full-force in 2013, launching its Amplify TV platform, and now they’ve launched cookies-based retargeting for brands, allowing them to use their e-mail lists and cookie IDs to serve users applicable ads. This is standard practice for other online services, but has come with some concerns over privacy. Twitter’s senior director of product, Kevin Weil, assures the public that all information is non-identifiable and there will be the option to opt-out of the promotions within Twitter’s interface, or via Do Not Track.