Purpose: The paper aims to set out challenges that libraries face while developing their Digital Library capabilities and capacity and propose an approach to estimating the costs for these functions. There is a skills challenge as well as an organisational challenge. The opportunities to build new teams or re-train existing staff are discussed. Design/methodology/approach: The approach builds on a 2008 paper about Digital Library economics and discusses the changes in the environment since then. A model is described in which a library takes on the full responsibility for building and operating a Digital Library function in-house. This is used to benchmark other options such as managed services, outsourced infrastructure and "cloud" se...