Background: We are strong advocates of evidence-based software engineering (EBSE) in general and systematic literature reviews (SLRs) in particular. We believe it is essential that the SLR methodology is being used constructively to support software engineering research. Aim: This study aims to assess the value of mapping studies which are a form of SLR that aims to identify and categorise the available research on a specific topic. Methods: We use a multi-case, participant observer case study using five examples of studies that were based on preceding mapping studies. Results: We identified 13 unique benefits that can accrue from basing research on a preceding mapping study of which only 2 were case specific. We also identified 9 problems associated with using preceding mapping studies of which two were case specific. Conclusions: Mapping studies can save time and effort for researchers and provide baselines to assist new research efforts. However, they must be of high quality in terms of completeness and rigour if they are to be a reliable basis for follow-on research.