Sales of the 2014 Chevy Silverado were up 10% last month, despite incentives that trailed Ford's by a wide margin. Photo credit: General Motors Co.

Most automakers' October sales fell short of Wall Street's expectations, as the government shutdown made consumers hesitant to buy. The big exception was General Motors (NYSE:GM), which saw its U.S. sales rise almost 16% on the month -- twice the gain expected by analysts.

GM had a lot going for it last month, but one big thing was its all-new pickups. Sales of the new 2014 Chevy Silverado and its GMC Sierra sibling were up, after posting a big drop in September while Ford's (NYSE:F) F-150 sales boomed. 

What changed for GM? As Motley Fool contributor John Rosevear explains in this video, GM changed the prices on its all-new pickups, and that helped -- but not in the way you'd expect.