Board Thread:Questions and Answers/@comment-70.210.57.25-20160219043113/@comment-3544775-20160224131200

Obviously because they are more popular, sell more and publishers though they will succeed. Not to mention when the first english vol was released, Bleach had 12-13 vols in jp and One Piece had 27-28vols (and the decision to license those probably came 6-12 months before that). Also One Piece had ongoing anime which was licensed soon after and Bleach anime also started soon after the license.

It's one thing to publish 5-10 vol series. If it doesn't succeed, losts won't be that big. But it's another thing to publish 30+ vols and to fail. That's why obviously when they go for long series, they seek guaranteed money back and are not that much willing to take risks.