I just submitted a review of a very long paper. In science we spend a good amount of time doing “peer review”, which means we look over every piece of work to be published by our colleagues to try to help each other present our work as accurately and clearly as possible. It’s not something we get paid for, but it’s part of what makes science work, so it has to be done.
It took me three days to do this review — it was a really long article. I don’t really have three days to spend on something like this. Maybe I should have said no. But I do feel richer for having done it, even if financially I’m 3 days poorer.