In the past month, Taboola announced a version of its content recommendation app will come installed on select lines of ZTE phones; Revcontent launched Engage.im, an invite-only infinite scroll of publisher content it said has been in development for three years; and Outbrain launched Sphere, an invite-only publisher content recommendation network. Outbrain also ran a price promotion for premium publishers during the first quarter of 2018 to entice them to buy more traffic through its service.