The reason this story is so interesting is because the characters come alive. They are full-bodied characters with good and bad traits with a wide range of feelings and emotions. They are compelling because they are real human beings not caricatures. The Sultan himself is a complex character. He has a love of literature and rebels against the tyrannical rulers who seek to destroy his books. He believes that his country must modernize and move forward in order to succeed. He is a bustling and ambitious capitalist. But when it comes to his family he is unable to so easily throw off the past. Despite his modern ideas and talk of freedom he is an authoritarian patriarch who harshly and often coldly rules his household. But Seierstad doesn't demonize him either but rather reveals the difficulty in transitioning from a world ruled by tradition and strict rules to a more open and free society. Try as he might Sultan can't envision a family all that different from the one his father ruled.

The book is full of interesting characters:
- Sultan's son Mansur, who often has good intentions but finds himself trapped as the eldest son between responsibility and the freedom that is just out of reach. He realizes that he has more than others but can't quite bring himself to do the right thing. He alternates between rebellion, promises of virtue and faith, and resignation of his fate.
- Sultan's youngest sister Leila, who is forced to be the servant for the entire family who yearns to break out and make a place for herself in the world. She struggles to get a job as a teacher and hopes to be married to a man that will allow her to escape the life of servitude. Despite these longings, however, she can't break free from the weight of social norms and tradition; she seems almost resigned to a fate of "eating dust."
- Sultan's wives, Sharifa and Sonya. Sonya the young girl brought in as Sultan's second wife, shy and simple minded - interested in nothing but her new husband. Sharifa, shamed and embarrassed by her husband's actions, yet compelled to continue to do the work of a dutiful wife with less and less of the rewards.
- Aimal, Sultan's youngest son, twelve years old yet forced to work twelve hours a day in a small booth in a hotel lobby. Deprived of an education and seemingly of a future beyond the small walls of the booth, Aimal sprits are slowly being crushed.

The story of Aimal is a good illustration of the melancholy but insightful storytelling in the Bookseller of Kabul. Aimal is in the lobby of the hotel when the new Minister of Aviation is killed:

He returned to the dreary room, sat down behind the table, ate a Snickers. More than four hours to go.
The cleaning man swept the floor and emptied the wastepaper basket.
"You look so sad, Aimal."
"Jigar khoon," said Aimal. My heart bleeds.
"Did you know him?" asked the cleaning man.
"Who?"
"The minister."
"No," said Aimal. "Or, yes, a little."
It felt better that his heart bleed for the dead minister than for his own lost childhood.

What is amazing about the portraits that Seierstad draws is that she captures the fatalistic nature of much of life in Afghanistan, even amongst this "middle class" family, but she also gives them their dignity. They have dreams and hopes; they have feelings and desires even if in the end they lack the strength to overcome the burden of their circumstances. She avoids the trap of idealizing them but she also doesn't look down on them because they refuse to play the part of social revolutionary. Given the personal feelings and emotions that she must have felt, Seierstad does a remarkable job of simply telling the character's stories without interjecting her own views.