Matchmakers: The New Economics of Multisided Platforms by David S. Evans
Given that matchmaker businesses include stock exchanges, newspapers and shopping malls the claim that the field of economics only 'discovered' them in 2000 is the most interesting fact in this book. It doesn't sound like it can possibly true and either casts serious doubt on the credibility of the authors or on the entire field (including the authors).
Looking past the amazing recent discovery of multi-sided platforms the book is very light on any actual theory beyond the trivial - for example pricing may include a subsidy to one side and platform ignition is hard. Really. There are some good anecdotal accounts of specific businesses and there is a small amount of insight to be gained here. Overall I'd say avoid though.