More than 90% of United States public libraries offer e-book lending services to their users. Libraries sign contracts with vendors that provide digital content to them. E-book usage has increased year by year, and e-book lending is now regarded as a standard service. Although several lending models coexist, this article examines the most popular model, which allows users to download digital content to their own devices, and evaluates the condition of the e-book lending service based on their latest statistics. Then the article discusses three major issues identified as the e-book lending service gains popularity: 1) a change in vending platforms, 2) higher prices and/or circulation restrictions imposed by publishers, and 2) the protection ...