You are still "the product" even if google derives secondary benefits - because you are using firefox. Google doesn't pay the other forks of firefox money (at least, as far as i know). It's because you aren't using those browsers (you as in the royal you).

I didn't say you being a product is bad - but it does not align customer with software company. You may be OK with being sold as a product to google, as this relationship currently isn't damaging. But what if a future offer which would damage you is taken by mozilla because it's profitable?