2005–2010: Career beginnings and international recognition
Kardashian first became known to reality-television audiences on the 2005 series, Filthy Rich: Cattle Drive, on which she earned money for charity. In February 2007, a sex tape made by her sister Kim and former boyfriend Ray J in 2003, Kim Kardashian, Superstar, was leaked, which largely contributed to her rise to prominence. Later that year, Kardashian's mother, Kris Jenner met with Ryan Seacrest to pursue a reality television show based on her family. Seacrest, who had his own production company, decided to develop the idea, having the popular family-based show The Osbournes in his mind. The show eventually was picked up to air on the E! cable network, with Kardashian's mother acting as the executive producer. The series debuted on October 14, 2007, and revolved around Kardashian, along with her parents, mother Kris and stepparent Caitlyn as well as her siblings Kim, Khloé, Kendall, Kylie and Rob. The title of their reality television series Keeping Up with the Kardashians, and it chronicles the personal and professional lives of their family members. The series proved successful for E!, the network on which it is broadcast, and led to several spin-offs.
In April 2009, Kardashian and her sister Khloe announced that they were contracted to star in a spin-off that would follow their move to launch a D-A-S-H store in Miami, Florida. The series, Kourtney and Khloé Take Miami, debuted on E! on August 16, 2009. Kardashian and her sisters Kim and Khloe made a cameo appearance in the Season 3 premiere of the series 90210.
Kardashian and her mother opened children's clothing boutiques called Smooch in the Los Angeles area and New York City; the boutiques carry the brand Crib Rock Couture. With sisters Kim and Khloe, Kardashian co-owned D-A-S-H, a clothing boutique in Los Angeles, Miami, New York City, and a pop-up store in the Hamptons. It shut in May 2018.
In the spring of 2010, Kardashian and her sisters released a clothing line for Bebe. In August 2010, Kardashian announced that she and her sisters were working on another clothing line called K-Dash, sold on QVC. Later that year, they also created a sunless tanner called Kardashian Glamour Tan. Kardashian co-wrote the book Kardashian Konfidential with her sisters Khloe and Kim; released in November 2010.