“This is a generation of kids that have learned to communicate, search and purchase on very small devices, like mobile phones,’’ said James McQuivey, Forrester Research media analyst. “This year is a guinea pig year, next year the move will be en masse.’’ The trends are already striking. Forrester Research projects that 15.5 million e-readers will be sold this year, a 50 percent increase over last year. While the firm does not break out sales by age, children are a growing customer base. When Barnes & Noble launched a digital library for children last October, it had 120 picture book titles; today it has 570, including classics such as Curious George and Corduroy. Similarly, publisher HarperCollins reports that young adult e-books have surged 125 percent year over year.