I know this topic was gone and over, and off-topic to boot, but just to explain this to appease Kaiten.Sama.
Here's the other chart. It is a real top ten. There's no doubt. I just don't know what top ten. It most definitely does not represent the top ten in total sales. Even better, it contradicts the top fifty.
Statistics are just numbers. It's what the numbers are hiding that has you confused. The Top 10 chart linked above does indeed list the "Estimated Accumulated Total Sale Number" of 2008 by manga series. The reason why Reborn outranks other series despite its lower per volume sales is easy to understand when you look at
how many new volumes of that series was released in 2008 (24 Dec 2007 to 16 Nov 2008, to be precise).
These are all the
new volumes released this year for Shueisha titles. (Only listed the Shueisha titles because they're easier to find at the moment.)
One Piece - vol 49-52 (4 volumes)
Naruto - vol 41-44 (4 volumes)
Reborn - vol 18-22 (5 volumes)
Bleach - vol 32-35 (4 volumes)
NANA - vol 19-20 (2 volumes)
Gintama - vol 22-25 (4 volumes)
Reborn released more volumes this year than the other series, so it has an advantage. The popularity of Reborn spiked this year. You think Shueisha's editors didn't push the Reborn volumes out faster to take advantage of that? Not only does Amano-sensei not ever take breaks in the magazine, the tankoubon are remarkably close to the magazine chapters. (Unlike Bleach.)
Lastly, total sales also include books released earlier than this year, so the hype of a series caused by movies or drama tie-ins will boost sales dramatically. (E.g. The Rookies and Nodame drama series did extremely well on TV, which boosted the manga sales. Ditto for the 20th CB and Nana movies.)