Some series have fantastic debuts, which overshadow the rest of their careers. Not these ones...
Call of Duty
The original Call of Duty in 2003 was made for PC, and as such is hard to determine the true sales of. However, as late as 2006, Call of Duty 3 sold a total of about 7.48 million copies. The explosion began with next year's Modern Warfare, which sold 18.46 million across platforms, culminating with over 30 million sales for Modern Warfare 3. This was a four-fold increase from 2006's release to 2011's.
FIFA
FIFA is one of the bigger series of the past few years, which makes its . The series began way back in 1993, and even as late as 2005's FIFA 06, it sold only about 5.43 million units across four platforms and three handhelds. Seven years later, FIFA 13 sold 8.18 million units on the PS3 alone, and 15.7 million across all platforms. This was an increase of about 189% over FIFA 06.
Final Fantasy
The original Final Fantasy, though moderately successful, only ever sold about 0.84 million copies on the Famicom and NES. Sales notably increased for entries III, IV, V, and VI, reaching 3.42 million sales by FF6. That was an increase of over 300%. And even FF6 paled in comparison to FF7, with 9.72 sales worldwide. That is an increase of over 1050% over the original! Oddly enough though, the best-selling Final Fantasy in Japan was FF8, which sold 3.63 million compared to the original's 0.52 million, an increase of about 600%.
Guitar Hero
Guitar Hero was a fad, but it was quite the big one. The original Guitar Hero in 2005 sold 2.38 million, but sales skyrocketed so that the third game in 2007, Legends of Rock, sold 16.3 million an increase of over 580%. Sure, sales plumetted pretty quickly, but the fad had a few years.
Madden
Like FIFA, Madden began in the 90's, but wouldn't peak for years, albeit a few years sooner. Madden NFL 2000 sold 2.36 million on the N64 and PS1, before the transition to the PS2 helped the series reach new heights. Madden NFL 06 and 07 sold 9.85 million and 9.98 million copies respecitvely, an increase of over 320% in a span of seven years.
Mario Kart
Mario Kart can be considered two parallel series on Nintendo's consoles and handhelds. On consoles, the Super Mario Kart on the SNES sold 8.76 million, which was later dwarfed by Mario Kart Wii's 35.28 million sales, an overall increase of over 540%. As Double Dash actually sold less than the SNES incarnation, that jump was over 400%. On the GBA, Super Circuit sold 5.47 million, a far cry short of Mario Kart DS's 23.17 million. This was an increase of over 320%.
Mario Party
The original Mario Party was obviously a hit, which is why so many sequels were made. But many N64 and GameCube entries never exceeded the original's 2.7 million sales. Mario Party 7 sold only 1.57 million, the worst-selling console entry other than the recent tenth game. However, Mario Party 8 sold 8.22 million total, over three times more than the original and over five times more than the previous iteration. The leap from the GBA entry to the DS entry was even more impressive, from 0.98 million to 8.9 million, a nine-fold increase.
Tekken
Tekken started in the arcades, but became a titan on the PlayStation in the 90's. The 1995 release of the original Tekken sold 3.24 million copies, an impressive number. This was only the beginning, as 1998's Tekken 3 would sell 7.16 million. This 120% increase is probably due to the inclusion of multiple bears as playable characters.
Youkai Watch
Youkai Watch is a young series, but has already shown a lot of growth. The original 2013 game sold 1.33 million copies, an already impressive number. The initial Youkai Watch 2 versions, Ganso/Honke, sold 3.14 million, while the Shinuchi version released a few months later sold 2.63 million, for a combined 5.77 million. This was an increase of 330% in under two years!
Anyone else know any great examples of series becoming much bigger over time?
Love and tolerate.
