From the same link:
From 2008 to 2013, the gun and ammo manufacturing industry had one of the stronger periods in its history, with revenue growing at an annual rate of roughly 8.4% to an estimated $14.7 billion in 2013, according to a report on the industry by research firm IBISWorld. The reports authors concluded that gains for the industry were driven in part by anxiety among its customers. Fear of a potential rise in crime contributed to unprecedented industry growth, the report stated. (In fact, nationwide, both property and violent crime rates fell over this period, according to FBI data.)
The impact of fear on gun sales was clear in the aftermath of the terrorist attacks on Sept. 11, 2001. The number of criminal background checks for firearm purchases considered a good proxy for gun sales jumped 22% in September of 2001 over the previous months levels, and another 19% that October.
Fear of crime isnt the only anxiety that drives sales: When gun owners believe that the government will pass new regulations limiting their access to firearms, many, not surprisingly, go out and stock up. Some analysts believe that was the case in the latter half of 2012, when two large mass shootings by lone gunmen one in Aurora, Colo., in which 12 movie-theater patrons were killed; another in Newtown, Conn., that killed 20 children and six school employees led more public figures to call for gun restrictions. From August to December of that year, Federal Bureau of Investigation background checks climbed a total of 82%, to 2.78 million in December, an all-time record and a 49% increase over December 2011, according to FBI data.
Those numbers seem to have translated into improved sales as well: Smith & Wesson reported that net sales for the year ended April 30, 2013, climbed 43% from the previous year, hitting a record $588 million, with fourth-quarter sales up 38% compared with a year earlier. And gun maker Sturm Ruger & Co. saw net sales in 2012 hit $491.8 million, up from $328.8 in 2011. Indeed, gun sales sometimes jump after events like mass shootings, and they jumped after the recent elections, says Robert J. Spitzer, a professor of political science at the State University of New York-Cortland and the author of four books on gun policy. Some people are afraid their access to guns will be restricted, so they buy; others buy them as a political statement to voice their disagreement with people who want to regulate guns.
Of course, Second Amendment absolutists and right-wing gun nuts will see this as "good news" because it means that their NRA-induced fear is justified, and that this country will continue to be flooded with lethal weapons. The entire right-wing American gun culture is based on paranoia: fear of government, fear of "scary looking" people, and fear of many other imaginary boogeymen.