Fitzgerald Cecilio

Robert Griffin III now owns the best selling NFL jersey in a single season with his No. 10 Washington Redskins.

He took the top spot from Brett Favre, who held the record twice -- with the New York Jets in 2008 and the Minnesota Vikings in 2009.

Griffin broke the record with still 3 months to spare as the NFL fiscal year ends on March 31.

The metric is based on sales of jerseys on the league's official Internet store, NFLshop.com. The NFL started keeping track only six years ago.

Improved sales is partly attbibuted to the league's change in its official apparel manufacturer this year from Reebok to Nike.

Redskins merchandise sales is also up in December by 252 percent from the same period last year, which is the highest percentage increase among NFL teams this month.

Fanatics spokesman Meier Raivich said that 87 percent of Redskins merchandise the company has sold since the start of the season has been purchased outside the Washington, D.C., Maryland or Virginia areas.

Everything related to Griffin is selling.

Adidas spokesman Michael Ehrlich says the company has sold out Griffin's line of socks at the premium price point of $20 per pair.

Robert Griffin III Overtakes Favre in NFL Jersey Sales - NFL 2012