From your link:
Among Canadian e-book buyers, Kobo was the most popular purveyor of e-reading devices—27% planned to use a Kobo device to read their next e-book. “Given Kobo’s Canadian roots, this isn’t surprising,” said Pamela Millar, BookNet Canada’s Director of Customer Relations. “But Kindle and Apple devices are not far behind.
Apple devices? They are including tablets as devices. scrapking's 47% number comes from a poll for dedicated eReaders. There is no conflict, approximately half of ebook consumers read on tablets or phones.