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Japan vs. Manga Piracy: $800m Losses & 100 New Pirate Sites in One Month
(torrentfreak.com)
This is a most excellent place for technology news and articles.
I would guess less than 2% of pirating users would have paid if unable to access. No accounting in these estimates for new fan recruitment, added word of mouth advertising generated, purchasing of brick and mortar licensed merchandise, purchase of additional digital media that may be harder to locate from pirate sources.