Toyota is busy these days counting how many of each model they have sold so far. After revealing that they’ve delivered over 10 million Camrys in the U.S., they are now bragging about the Prius hybrid, which recently passed the 3 million mark in the global market.

That is a significant milestone for the little car, which was introduced in 1997. As the world’s first mass-produced hybrid passenger car, the Prius didn’t see any competition for a long time, which kind of explains how they managed to sell that many of them. Toyota came up with something new and revolutionary, and reaped the rewards.

The second generation Prius followed in 2003, and the third generation in 2009. By that time Toyota had cut the costs of the hybrid system by two-thirds and increased fuel efficiency from 28 km/L to 38 km/L. So the world’s most famous green car continued strong as ever, and at the end of June, 2013, it passed the 3 million mark.

Toyota is going to have the devil’s own job coming up with a proper successor to the current Prius, something that can still cut it in a world full of fine hybrids and electric cars. But they are prepared. In the fiscal year ending March 2014, TMC expects to spend a consolidated 890 billion yen (790 billion yen unconsolidated) on environmental technology development, as well as on strengthening new platform and major component development.