Multiple studies have explored the factors underlying the evolution and maintenance of “monogamy”, sometimes with contradicting and contentious conclusions. These studies have been plagued by a persistent use of fuzzy terminology that often leads to researchers comparing “apples with oranges”. Additionally, a number of problems associated with many comparative studies hinder a clear appreciation of possible advances that have been made in the understanding of causes and consequences of the various aspects of “monogamy”, namely pair-living and sexual monogamy. These problems include an overreliance on secondary sources and associated lack of agreement between data used with data from the primary literature. A couple of minimal guiding principles for comparative studies (and indeed any research) are proposed, including the emphasis that perspectives of all participants need to be considered. This leads to the second part of the talk, which discusses an aspect that in the past has been somewhat neglected: the importance of “floaters” in the context of selection pressures in pair-living species. The floaters’ perspective and their impacts on local operational sex ratios, competition, and variance in reproductive success across a population need to be considered more systematically. It is tentatively suggested that the operational sex ratio is more variable, and that the strength of intra-sexual competition in pair-living animals is higher than often appreciated.