Definitely OpenAI. They’re not profitable and their core product is expensive to serve. They also have the disadvantage that their better models and features (eg agents, research, CoT, etc) are more expensive, but are better hooks to prove utility to new users - fundamentally they need a method to cheapen the cost of serving free users better features. Google can afford to see how it shakes out and the impact to OpenAI.

OpenAI already exploring and experimenting with different ad modalities privately. They’re also have a much better brand, so they might be able to avoid too much churn of customers.