Book excerpt: We analyse the roles of network connectivity and topology on the monopoly pricing of network goods which enable social interaction between consumers. Connectivity between network members induces the well-known network externalities effect, while the topological effect is caused by the incompleteness of the social network's linkage, and it has not been previously recognised in this context. We find that the topological effect counteracts, and dominates, the connectivity effect by reducing the monopoly's capacity to extract consumer surplus. Our results are seen to hold in real cases of social network businesses. The monopolist benefits from price discrimination based on consumers' social connections, but this has a social cost as consumer surplus loss is higher than the increase in profits, with the highly connected consumers being the primary losers. Therefore, privacy policies restricting excessive social profiling and tracking can have an antitrust role too. Our approach also extends the theory of multi-sided markets in relation to the underlying relations graph of different market sides.