This trip is the exact reason why Fusaichi Pegasus was the Thoroughbred Times' Top Ranked Stallion this past year.
However, there is a great discussion here about the merits of how exactly you count progeny earnings.
Since he kinda fell off the map after his first few crops, more trainers are getting to train his progeny. So, he gets to travel around the world, breed 200+ mares per season (this year his two will be at Ashford in Lexington [wrapping up now] and LaMission in Argentina) and his numerous offspring are BOUND to put up some gawdy earnings en masse.
Traditionally, his colts and fillies are "sprited" and stubborn. (I know, my 2yo is a huge pain in the ass). Larger barns (Pletcher, Asmussen, etc) have so many horses that it is hard to focus on particular young'un that is hard to train and maintain. Put more of them out there, at a lower investment cost (15k stud fee), and you get these horses into the hands of trainers that spend more time on each animal and can coax the results out of each one.
FuPeg is 7th right now, in terms of earnings. You can check out his breakdown here: http://www.thoroughbredtimes.com/breeding/general-sire-list.aspx
Having seen FuPeg in person, he really is a collection of parts, albeit great looking ones. There are classic looking horses: Majestic Warrior to name one. There are sprinter-looking horses: Munnings is a great example. Some literally look like milers: Artie Schiller being the archetype. But FuPeg just looks like a bunch of great parts of horses cobbled together with his signature long, arched neck. Definitely an interesting (but very specific) horse to breed to.