There's a ludicrously large backlist in books and this could mean a massive new revenue stream.

书多得令人匪夷所思，这可能预示一股新的庞大现金流。

Recently, several big American publishers have declared themselves eager to move their entire backlist of books into the digital sphere.

近，美国几家大型的出版商声明他们将把自己的书籍字领域。