What a firm does is more revealing than how much it makes, but firms are
often described with economic metrics. Here, we characterize what firms read,
their information footprint, using a data set of hundreds of millions of
records of news articles accessed by employees in millions of firms. We relate
a firm's information footprint with economic variables, showing that the former
grows superlinearly with the latter. This exaggerates the classic Zipf's law
inequality in the economic size of firms and reveals an economy of scale with
respect to information. Second, we discover that the reading habits of firms
are of limited diversity. Firms above a certain size reduce the relative
diversity of information they consume, indicating the sudden onset of a
coordination cost. Third, we reconstruct the topic graph firms inhabit and
propose a simple model of firm growth in this space. Firms adhere to a mixed
strategy of local exploration and recurrent exploitation on the topic graph.
This strategy is costly, and we predict that firms consume a prodigious amount
of information over their lifetime because they cumulatively add to their
information portfolio instead of diversifying. This shows that the costs of
information and the structure of the space of ideas provide a useful but little
explored perspective on firm growth