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

书目多得令人匪夷所思，这可能预示一股新庞现金流。

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

最近，美国几家版商声明他们将把自己书籍搬到数字领域。