[summerlight]

> Moreover, the cost per ad will be massive given how expensive the inference is.

The existing system still can do a nice job to predict value per query, so they'll apply it to perhaps only 1~5% of queries. It's still expensive though, but acceptable if the additional cost is meant to be transient over 1~2 years.

> Anyone can incorporate a bunch of DDG results to a self-hosted good-enough LLM

Perhaps (much) less than 0.01% of population? Technically, anyone can self-host their own blog but not many do that.