[1][2][3][4] The film traces the use of public relations tactics that were originally developed by the tobacco industry to protect their business from research indicating health risks from smoking.

The central concern of the film is the ongoing use of these tactics to forestall governmental action to regulate greenhouse gas emissions in response to the risks of global climate change.

'"[8] A. O. Scott wrote in The New York Times that Swiss' "presence, and the animated playing cards that sometimes fly across the screen, feel like a glib and somewhat condescending gimmick, an attempt to wring some fun out of a grim and appalling story.

[13] Justin Chang wrote for Variety that the film is "An intelligent, solidly argued and almost too-polished takedown of America’s spin factory — that network of professional fabricators, obfuscators and pseudo-scientists who have lately attempted to muddle the scientific debate around global warming — this is a movie so intrigued by its designated villains that it almost conveys a perverse form of admiration, and the fascination proves contagious.

"[14] William Goss wrote for The Austin Chronicle that "Merchants spends much of its running time exposing trends of political subterfuge before working in an earnest call to action regarding climate change.