2011 Nissan Leaf

In was late July when Carlos Ghosn, Nissan chief executive officer, stated that "with more than 10,100 electric Nissan Leaf vehicles already sold worldwide" the Japanese automaker is "clearly the global leader in zero emission mobility."

Now, that number is over 15,000. That's the estimated number of Nissan Leafs sold worldwide since its initial debut in Japan and here in the States in late 2010, according to the Detroit Free Press. Officially, AutoblogGreen has tracked more than 13,620 Nissan Leafs sold across the globe, but with Japan's September sales results still unknown – and sales across most of Europe a question mark – 15,000-plus seems an accurate assumption.

To put that 15,000-unit number in perspective, cumulative sales of the Japan-only Toyota Prius hit approximately 3,000 units in its first year (1997), soared to 20,000 by the end of 1998 and topped 35,000 units by the close of 1999. Now a global vehicle, the Prius reached worldwide sales topping three million in March of 2011. To compare the Leaf to other plug-ins (albeit very different machines), the Tesla Roadster has sold roughly 1,800 units and the Chevy Volt is sitting at around 4,000 units sold.

Will the Nissan Leaf experience the same sales boom as the Prius? Or will the electric hatch someday fizzle? Drop us your thoughts in Comments below.