>I don't get it, what other sense is there?

Obvioulsy the TYPE and RETURNS of some cost.

>These both seem like user acquisition pitches. The real difference with programmatic access is that you'll likely get users hitting the cap and paying for more usage if they like the product.

50 searches from the web feel way more generous to a user than using the agent (most wont even hit them), hitting the 50 cap in like 10 minutes, and being negative about the whole experience.

>... which is exactly what I was suggesting for API use.

Which is exactly why it wouldn't work well for API use with such cap.