Following in Amazon's footsteps, Barnes & Noble announced yesterday that its Nook e-reader is now the company's best-selling item ever. What's more, the retailer is now selling more e-books on its website than old-fashioned, papery things. Though Barnes & Noble is being shy about releasing actual sales figures, it did say that more than 1 million e-books were purchased on Christmas Day alone, that it has sold "millions" of its various Nook devices, and that its Nook Color was its top-selling gift over the holidays. See PC Mag for the full details. (More Nook stories.)