Netflix is offering early signs of the popularity of its new ad-supported tier. Oppenheimer analysts say in a research note that the 23 million monthly active users on the ad tier announced by the company’s president of advertising, is up from 15 million in November and 5 million in May. They say the accelerating growth suggests Netflix has upside on its subscriber numbers this year. The analysts raise their full-year estimates for subscriber net adds and increase their price target to $600 a share from $475.