The faith-based film Fireproof, starring Kirk Cameron, is enjoying impressive advance ticket sales this week according to Harry Medved of Fandango. It is the story of a firefighter who finds that his most difficult challenge is finding a way to give his wife the love and intimacy necessary to keep their relationship strong. It is not until he turns to God for help that he begins to find a way to let her know how much she means to him.

It opens in more than 800 theaters this Friday, small in Hollywood terms but an extraordinary achievement for a film that cost only $500,000 and was made mostly by amateurs from a film-making ministry in Albany, Georgia. “No one is expecting it will rule the box office,” Medved told me, “but it has made an impressive beginning.”

Church-based “action squads” have been buying tickets in bulk, a powerful reminder to Hollywood that an under served audience will respond positively to a film like this, even without a lot of ad support. “It’s a great couples’ movie,” said Medved. “When’s the last time a movie improved your marriage? We get a lot of movies about falling in love or about temptations away from marriage but this is a film about making a marriage work.” Couples can learn from this film about how to give fully of themselves for a strong and lasting relationship, no matter what their religious beliefs.

“For moviegoers who plan to see a smaller release on opening weekend, online ticketing is the way to go,” says Fandango Chief Operating Officer Rick Butler, who adds that advance ticket sales for “Fireproof” continue to be “healthy.”