Question: The novel Betrayal contributed to Danielle Steel's sales success in selling over how many copies?

Context paragraphs:
Danielle Steel's 'Palomino': Danielle Steel's Palomino is a 1991 television movie based on a novel by Danielle Steel about the romance between a photographer and a cowboy.  A subplot involves a romance between characters played by Rod Taylor and Eva Marie Saint, who acted together years earlier in "Raintree County" (1957) and "36 Hours" (1964).  The film aired on October 21, 1991 on NBC.

Daddy (1991 film): Daddy, also known as Danielle Steel's Daddy, is a 1991 television film directed by Michael Miller.  The film is based upon the 1989 novel "Daddy" written by Danielle Steel.

Kaleidoscope (1990 film): Kaleidoscope, also known as Danielle Steel's Kaleidoscope, is a 1990 made for television romantic drama film directed by Jud Taylor.  The film is based upon the 1987 novel of the same name by Danielle Steel.

Danielle Steel's A Perfect Stranger: Danielle Steel's A Perfect Stranger, also known as A Perfect Stranger (just like the name of the romance novel by Danielle Steel from which the film takes origin) is a 1994 American romantic-drama television film directed by Michael Miller, whose most important element is the love triangle which characterizes it.  The special effects were created by Brock Jolliffe.  The film is set in San Francisco, California, and was released in the United States in 1994 where it aired on NBC.

Heartbeat (1993 film): Heartbeat, also known as Danielle Steel's Heartbeat, is a 1993 television movie directed by Michael Miller and written by Jan Worthington based upon the 1991 novel of the same name by Danielle Steel for NBC.  The film tells of a man who was abused as a child and, as a result, has no interest in having children of his own.  When Adrian reveals to her husband that she is pregnant, her husband pressures her to have an abortion.  Adrian rebuffs her husband's orders and he neglects her.  The showrunner and Adrian's boss for the soap opera she writes and produces becomes romantically involved with her, eventually marrying her and helping Adrian raise her baby.  John Ritter stars as the television producer, Polly Draper as Adrian, and Kevin Kilner portrays Adrian's husband.

Betrayal (Steel novel): Betrayal is a novel by Danielle Steel, published by Delacorte Press in July 2012.  The book is Steel's eighty-sixth novel, and (including non-fiction and children's books) her 104th book overall.  It reached number 3 in the New York Times hardback fiction bestsellers chart.  It is also available in audio book, read by Renee Raudman.

Danielle Steel's Star: Danielle Steel's Star is a 1993 American made-for-television film starring Jennie Garth, Craig Bierko, Terry Farrell, Penny Fuller and Mitchell Ryan.  This film is based on the novel "Star" by author Danielle Steel and is set in the 1970s.  It was directed by Michael Miller and written by Danielle Steel and Claire Labine.  Crystal Wyatt's singing voice during the song "Timeless Love" was performed by Megon McDonough (credited as Megan McDonough).

Danielle Steel: Danielle Fernandes Dominique Schuelein-Steel (born August 14, 1947) is an American novelist, currently the best selling author alive and the fourth bestselling fiction author of all time, with over 800 million copies sold.

Safe Harbour (film): Safe Harbour, also known as Danielle Steel's Safe Harbour, is a 2007 direct-to-video film directed by Bill Corcoran, based upon the 2003 novel of the same name by Danielle Steel.

Mixed Blessings (film): Mixed Blessings, also known as Danielle Steel's Mixed Blessings, is a 1995 NBC television film directed by Bethany Rooney.  The film is based upon the 1985 novel of the same name written by Danielle Steel.  It contains three stories of couples who are facing parenthood for the first time.  Scott Baio, Bess Armstrong, Gabrielle Carteris, and Bruce Greenwood lead the all-star cast.

Supporting paragraphs: Betrayal (Steel novel) Danielle Steel
Answer: over 800 million copies sold