User blog comment:Udarsha45/Top Selling Series And Volume of 2014/@comment-5398287-20141202170541/@comment-1351982-20141202173224

If I were to take a guess, it might be because volume 64 was delayed a month and landed in September and 65 was released in October. Two volumes back-to-back may have turned some people off or assuming that at this point most bleach fans in Japan are probably older and don't have as much money to burn. That's my guess anyway. Shueshia should have delayed 65 a few weeks to the end of October as to not cut into 64's sales.