Fifty Shades Of Grey looks set to notch up another record and become the fastest selling DVD of the year so far.
The erotic drama has shifted 379,000 copies after three days on sale, according to the Official Charts Company.
If its popularity continues during the rest of the week, it will beat this year's current top-seller, The Hobbit - Battle Of The Five Armies, which sold 477,000 copies in its first week.
Paddington is the only other video to sell over 400,000 copies in its opening week this year, with 464,000.
Official Charts Company chief executive Martin Talbot said: "This is a quite stunning success for Fifty Shades Of Grey, which looks on course to outstrip the first week performance of both The Hobbit and Paddington by this Sunday."
The figures were released after the latest instalment in author EL James's sadomasochistic saga smashed UK sales records, selling more than 647,000 copies in three days.
The new book, called Grey, is a retelling of the first novel in the hit series about an affair between mysterious tycoon Christian Grey and lover Anastasia Steele, from the point of view of its title character.
Figures released by publisher Arrow Books show sales of 385,972 physical copies and 261,429 ebooks - a total of 647,401 - giving the biggest first week sales for an adult book.