Grdina at the XBIZ Awards on November 17, 2005
John G. Grdina|
October 11, 1967
|Residence||Paradise Valley, Arizona|
|Other names||Justin Sterling|
|Spouse(s)||Jenna Jameson (2003–2006)|
Grdina was born in Ohio to a wealthy cattle ranching family who immigrated from Karlovac, Croatia. He spent portions of his grade school years at Naples Christian Academy (NCH) in Naples, Florida and his high school years at Gilmour Academy, a prep school in Gates Mills, Ohio. He attended the University of San Diego majoring in business and psychology.
After graduating college, Grdina pursued a variety of careers and business ventures until 1992, when he began investing in adult films directed by Michael Ninn. From 1995 to 1999, he wrote and directed several pornographic films in Ninn's style, often under the name 'Michael Santangelo, Justin Fine and Justin Sterling.
Grdina met Jenna Jameson, already a famous porn star, in 1998. They married in a Roman Catholic-style ceremony on June 22, 2003. The couple resided in Scottsdale, Arizona in a 6,700-square-foot (620 m2) Spanish-style mansion purchased for $2 million in 2002. They later moved to Paradise Valley in a 10,000 sq ft (930 m2) home for $4.5 million.
In 2000, Grdina co-founded ClubJenna, first as an Internet pornography company then as a multimedia adult entertainment business. On June 22, 2006, Playboy Enterprises announced the acquisition of Club Jenna and related companies in conjunction with personal service agreements by both Jameson and Grdina.
Grdina produced, directed, and wrote several Club Jenna films including Briana Loves Jenna, The Masseuse, I Dream of Jenna, and Krystal Method. Grdina also acted in some of these films, as the only man that Jameson would have intercourse with on screen.
- 1998 AVN Award – Best Videography – Diva, The Series (shared with Barry Harley)
- 2004 NightMoves Award – Best Director (Fan’s Choice)
- 2005 AFW Award – Best Actor – The Masseuse
- 2005 AVN Award – Best Actor (Film) – The Masseuse
- 2005 AVN Award – Best Couples Sex Scene (Film) – The Masseuse (shared with Jenna Jameson)
- 2005 AVN Award – Best Editing (Video) – Bella Loves Jenna
- 2007 AVN Award – Best Editing (Film) – Jenna's Provocateur (shared with Johnny 5)
- Dnevno.hr Ratko Martinović: Loš PR u dijaspori - Koje su svjetski poznate osobe podrijetlom Hrvati, a da to niste ni znali, 28. listopada 2012. (Croatian)
- "The (Porn) Player", by Matthew Miller, Forbes magazine, July 4, 2005
- Brand Access Forum May 8, 2006 Los Angeles, California speaker profile. Archived from  on 2006-05-08 by the Internet Archive
- "U novom SVIJETU sve o PORNOGRAFSKOM MOGULU iz Karlovca: Kako se zaljubio u Jennu Jameson i stvorio američku PORNO SCENU". jutarnji.hr. Retrieved 2017-07-14.
- Justin Sterling on IMDb
- "Justin Sterling" Archived 2006-10-21 at the Wayback Machine. page about the director at lukeford.com
- "At Home with Jenna Jameson: Off Camera, Cashmere and Crosses" by Dinitia Smith, The New York Times, April 15, 2004
- "Playboy gets more hardcore with new acquisition", by William Spain, MarketWatch, June 22, 2006
- "NoHo Sees Hangover Defense Sales at $100 Million". Bloomberg.
- "Jay Grdina, NoHo". CNBC. Retrieved 2017-07-14.
- Powell, Brian. "Jenna Jameson's husband accused of assault". East Valley Tribune. Retrieved 2017-07-14.
- "Jenna Jameson files for divorce", United Press International, December 12, 2006
- "Club Jenna exec shares tips on being a good PV neighbor". www.azcentral.com. Retrieved 2017-07-14.
- "AVN Awards - 1997". RAME. Retrieved 2015-03-03.
- Dirty Bob (2004-09-21). "Winners of the Nightmoves Entertainment Awards Announced". AVN. Retrieved 2015-03-03.
- Chip Baker (2005-04-27). "Jameson, Sterling Earn AFW Honors". AVN. Retrieved 2015-03-03.
- "2005 AVN Awards Show Winners Announced". AVN. 2005-01-08. Retrieved 2015-03-03.
- "2007 AVN Award Winners Announced". AVN. 2007-01-14. Retrieved 2015-03-03.