The average lawsuit costs the defendant about $122 million, and the median loss is $20 million. According to the BU study, about nine percent of the lost wealth goes to what are politely known as non-practicing entities, NPEs, and more commonly known as patent trolls. The rest simply evaporates as legal fees, costs of lost business, management distraction, and diversion of resources from product development.
Of course, every out of pocket cost is revenue for somebody else. And "management distraction" and "diversion of resources from product development" is, for competitors, a "useful" development.