if that is your day to day activity, you were improving performance of the company's flagship product which launched to over $5 million in sales
Already there are more steps. You know he didn't sell that himself, a sales person did, and the link between performance and number of sales is unclear without knowing the product. So, to me, the $5 million number is nice ('ok so he was trusted to work on that important product') but feels a bit irrelevant when asking for a specific offer increase.
For whatever reason, it doesn't convince me that this candidate in particular couldn't have been replaced by another candidate for the same result. In the example of a sales person, I'm more easily convinced that s/he was influential in the result. edit: I guess it's because sales is so much more of a "people" job than engineering.
But maybe I'm just pointing at what you've been saying: take a job closer to the money…