Modern people, mainly used in electronic equipment, and seldom-used books and to read more information, they will start from electronic equipment at hand, so the eBook to pop.
Modern people, mainly the use of electronic equipment, and rarely used books to read more information, of course, they will start from the electronic device at hand, so e-books to be popular.
Modern people, the main use of electronic devices, and rarely use books, to read more information, they will certainly start from the electronic devices on hand, so e-books can be popular.