For my lab, the end product is a huge file of genomic data, for which people spend up to thousands of dollars of grant money, so people come here, do their work and leave.
For a newspaper site, for example, the goal is to get people reading, which exposes them to ads, which pay the bills. Here, "time spent on site" is exactly the metric at play.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.