Peer-reviewed papers are the major currency in the realm of science. Without an appropriate number of publications in high-quality journals, scientists do not get university positions, are not promoted, and fail to get grants to fund their research. Decisions made about authorship are not always straightforward, as accepted practice sometimes conflicts with other ethical guidelines or "rules of thumb," such as fairness, reciprocity, and sponsorship. This article examines how and why "highly productive" life scientists in universities make these important decisions. The findings illuminate the idiosyncratic nature of authorship decisions, the important role that context plays in scientists' decision-making about authorship, and how authorship often is a commodity exchanged among scientists. Concluding comments focus on the significance of studying "everyday ethics" and their potential impact on disciplines and higher education institutions.