2ND UPDATE, SUNDAY 11:15 AM: 20th Century Fox Home Entertainment today announced avatar_dvdthat James Cameron’s AVATAR 2D flew off shelves to become the fastest-selling Blu-ray of all time after just four days in U.S, and Canadian stores. Excluding rental sales, it sold 2.7 million Blu-ray units in North America, shredding Warner Bros’ The Dark Knight‘s Blu-ray sales record of 2.5 million units total. That means Avatar 2D in 4 days beat what Dark Knight did over 1 1/2 years. Retail sales of both AVATAR 2D’s Blu-ray and DVD discs have exceeded 6.7 million units since its launch last Thursday, on pace to be the best-elling title in recent history.

avatar dvd photo1UPDATED SATURDAY 4:55 PM: 20th Century Fox is saying that its First Day total AVATAR 2D U.S. and Canada sales of DVD and Blu-ray units were 3.2 million on Thursday. That breaks down to DVD 2M and Blu-ray 1.2M without rental sales. This easily beats the previous record set by The Dark Knight of 2.7 million (breaking down to DVD 2.1M, Blu-ray 600K). True, Summit Entertainment’s Twilight sequel New Moon sold 4 million units, but that figure is for First 2-Day sales. Avatar 2D‘s 2nd day numbers for Friday were close to 2 million, or a First 2-Day number of 5.2 million units. 20th Century Fox Home Entertainment flack James Finn is claiming to me Avatar 2D is now the #1 launch on both formats in the United States, France, and Germany. (Avatar 2D doesn’t street in the UK until Monday. France had the biggest First Day sales on DVD and Blu-ray ever with 400,000 units sold. Nearly 1/3 were Blu-ray.)

20thCenturyFox“Grocery and drug stores sold more Avatar [2D] in one day than they sold of The Dark Knight during its entire life on shelves,” Finn emails. “This shows that the audience for the home entertainment release far out weighs the fan boy base. It’s a cultural phenomenon…again. Employees and customers alike are dressing up as Na’vis in stores around the country, and this is a home entertainment release like no other.”

Finn also claims, “My sources are telling me that Best Buy has sold twice as many Blu-ray players as they normally do since the biggest movie of all time landed in stores. Mass merchants are estimating that Avatar Blu-ray sales are north of 50%, a remarkable percentage for the format and for the home entertainment category. I’ll have more of a read tomorrow morning, but Avatar [2D] is on track to do for Blu-ray what it did for 3D in theaters.”

This Avatar 2D unit is no-frills. A ”special edition” Avatar 2D comes out later in 2010, and the 3D edition in 2011.

Editor-in-Chief Nikki Finke - tip her here.