About four years have passed since the release of Nintendo DS games Pokémon Heart Gold and Soul Silver and Pokémon Black and White. As of March 2013, the Nintendo had sold 12.72 million copies of Pokémon Heart Gold and Soul Silver, seeing an increase of 50,000 unit sales from the prior year. Pokémon Black and White had sold 15.58 million copies as of March 2013, an increase of 160,000.
For games that have been around for four years and still manage to sell, even while newer Pokémon games are available, is quite impressive. In fact, new copies of the games can still be found in stores for about the same price as when they were initially released. This indicates the sales of the games are still going strong. It may be safe to say this is a trend for Pokémon titles, as up until this year, the 2007 Pokémon games, Pokémon Diamond and Pokémon Pearl, have sold 17.63 units as of March 2013. It seems the market for Pokémon games will certainly continue to sell long after their original releases.