They're less expensive than paperbacks.
They're environmentally responsible.
They can be read on a number of devices: computers, pda's, and specially designed e-readers.
Fonts can be enlarged.
Most e-books stay in catalogs for years. You don't have to hope to find an author's backlist from a used book store or an on-line auction site. Plus, there is an extensive and eclectic selection of books available for download.
You can store several books on a pda or a thumb drive for travel, or for standing in line, or waiting at the doctor's office, or to vote.
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