Two hundred days in, OpenAI has something Google and Facebook needed years to assemble: a billion-user surface, a self-serve pipe and a billion-dollar pace.

Ads have been rolled out for free users and those on the 399 rupee ($4) per month 'Go' plan.

The company is starting with 50 brands on free and lower-cost tiers, with a self-serve ad manager set to launch Sept. 4