  Software is increasingly produced in the form of ecosystems, collections of
interdependent components maintained by a distributed community. These
ecosystems act as network organizations, not markets, and thus often lack
actionable price-like signals about how the software is used and what impact it
has. We introduce a tool, the Scientific Software Network Map, that collects
and displays summarized usage data tailored to the needs of actors in software
ecosystems. We performed a contextualized walkthrough of the Map with producers
and stewards in six scientific software ecosystems that use the R language. We
found that they work to maximize diversity rather than quantity of uses, and to
minimize coordination costs. We also found that summarized usage data would be
useful for justifying ecosystem work to funding agencies; and we discovered a
variety of more granular usage needs that would help in adding or maintaining
features.
