The presence of emergent semantics in social annotation systems (e.g., Flickr, Delicious or BibSonomy) has been reported in numerous studies. Two important problems in this context are (i) the induction of semantic relations among tags and (ii) the discovery of dierent senses of a given tag. While a number of approaches for discovering tag senses exist, little is known about which factors influence the tag sense discovery process. In this paper, we analyze pragmatic factors, in particular we analyze if and to what extent different kinds of users and user behavior (i.e. how people use tags) influence a tag sense discovery task. In our experiments, we divide taggers into different pragmatic distinctions, including categorizers, describers, specialists and generalists. Based on these distinctions, we identify a small subset of users whose annotations allow for a more precise and complete discovery of tag senses, evaluated against Wikipedia disambiguation pages as ground truth. Our results provide further empirical evidence for a causal link between tagging pragmatics and semantics, and make a broader argument for including pragmatic factors in future semantic extraction methods. Our work is relevant for improving search, retrieval and browsing in social annotation systems, as well as for optimizing ontology learning algorithms based on tagging data.