The amount of corpus-based reseach in pragmatics and discourse analysis has been relatively small up to now. This is partly because these fields rely on context (Myers 1991) and the small samples of texts used in corpora tend to mean that they are somewhat removed from their social and textual contexts. Sometimes relevant social information (gender, class, region) is encoded within the corpus but it is still not always possible to infer context from corpus texts.
Much of the work that has been carried out in this area has used the London-Lund corpus which was until recently the only truly conversational corpus. The main contribution of such research has been to the understanding of how conversation works, with respect to lexical items and phrases which have conversational functions. 
Stenstöm (1984) correlated discourse items such as well, sort of and you know with pauses in speech and showed that such correlations related to whether or not the speaker expects a response from the addressee. Another study by Stenstöm (1987) examined "carry-on signals" such as right, right-o and all right. These signals were classified according to the typology of their various functions e.g.:
The availability of new conversational corpora, such as the spoken part of the BNC (British National Corpus) should provide a greater incentive both to extend and to replicate such studies, since the amount of conversational data available, and the social/geographical range of people recorded both will have increased. At present, quantitative analyses of corpus-based approaches to issues in pragmatics have been poorly served. Hopefully this is one area which will be exploited by linguists in the near future.