Only nine percent of new Netflix subscribers in the US opted for the streaming service’s new ad-supported streaming tier last month, according to data from analytics firm Antenna. That’s compared to the 15 percent of new signups that reportedly opted for competitor HBO Max’s ad-supported subscription during its launch month in 2021. Netflix’s “Basic with Ads” plan launched on November 3rd at $6.99 a month, compared to between $9.99 and $19.99 per month for an ad-free…