Sony's 9-year-old PlayStation 2 has actually been selling well for all these years, thanks in part to its huge library of great games. But thanks to a price drop at the end of March that sent the console down to $99, now the PS2 is even outselling Sony's newer, better PS3.

Sony sold 172,000 PS2s in the U.S. in April, according to research firm NPD Group. That's a 38% increase year-over-year. Meanwhile, it sold just 127,000 PS3s, down 32% year-over-year.

Even better: The cheaper PS2 may have also cut into Nintendo Wii sales, which was the whole plan. Nintendo sold 340,000 Wiis in April, down 52% year-over-year.

Price elasticity at work! And exactly why Sony is finally preparing to cut prices on the PS3.