Robert Seethaler’s novel A Whole Life, about a farmhand struggling to adapt to the modern world, has now sold over 600,000 copies in all formats in Germany. Its publisher believes the short novel–it’s only 160 pages–was helped by strong word-of-mouth from indie booksellers.

Book title: Ein ganzes Leben (In English: A Whole Life)

First published in: July 2014 by Hanser Berlin, an imprint of Carl Hanser Verlag

Format: Hardcover. (The paperback edition was published by Goldmann on January 18.)

Author: Seethaler, who was born in Vienna in 1966, has worked as a theater, television, and film actor. Pror to A Whole Life, his most successful novel was Der Trafikant (The Tobacconist). A Whole Life is his first book published by Hanser.

Acquiring Editor: Karsten Kredel

How It’s Done: The book, which has been performing well since it was released in hardcover is currently #8 on Der Spiegel‘s paperback bestseller list. It has been in the top 10 for 42 weeks this year. Farrar, Straus and Giroux published the novel in the U.S. in September. Translation rights have sold in 28 territories to date and, according to Hanser, the novel was the house’s top seller in 2014. (In 2015, A Whole Life was Hanser’s second-best performing title.)

Why It’s Working: Kredel cites the independent book trade as the key to the success for A Whole Life. After advanced copies were sent out in 2014, he said booksellers uniformly came back with endorsements and positive quotes. (Independent book shops account for 45% of all German sales.) Kredel said he had never worked on a book that so many booksellers raved about and that “any glitzy marketing campaign would have been dead wrong–we relied on word-of-mouth, and it worked.”