From "The Economic Structure of Intellectual Property Law"

By William M. Landes, Richard A. Posner, pp. 168-9.

An entirely different benefit of trademark protection derives from the incentives that such protection creates to invest resources not in maintaining quality but in inventing new words [...] or symbols or, less clearly, design features used as trademarks, such as the shape and color of the Perrier bottle or the shape of the Ferrari automobile; but for the moment we confine our attention to words. Trademarks improve the language in three ways. They increase the stock of names of things, thus economizing on communication and information costs in the ways just suggested. They create new generic words -- words that denote entire products, not just individual brands. "Aspirin," "brassiere," "cellophane," "escalator," "thermos," "yo-yo," "dry ice," and a number of other names of common goods were once trademarks -- and, whatever courts may say, "Kleenex," "Xerox," "Velcro," and "Rollerblades" are widely used to denote entire products as well as particular brands [...] Trademarks further enrich language by creating words or phrases that people value for their intrinsic pleasingness as well as their information value, such as "Pheremon" perfume and "Swan's Down" cake mix. A study in 1985 found that the frequency of brand names in best-selling American novels was increasing rapidly [...] with generic names achieving an impressive frequency of 160 generic names per 10,000 words [...]