Buzzed-about Facebook drama The Social Network opened solidly at the North American box office this weekend, topping the domestic chart with an estimated three-day tally of $23m.

The weekend’s other new releases both disappointed, with Case 39 taking an estimated $5.35m and Let Me In an estimated $5.3m.

Directed by David Fincher from an Aaron Sorkin script, The Social Network has been generating blogosphere buzz for months. Sony, which co-financed the $40m project with Relativity Media, opened the film in 2,771 theatres, for an average of $8,300 per theatre. The $23m opening compares to the $26.9m Christmas 2008 debut of Fincher’s The Curious Case of Benjamin Button, which went on to gross $127.5m domestically.

With Jesse Eisenberg, Andrew Garfield and Justin Timberlake starring as the key figures behind the launch of the Facebook phenomenon, The Social Network was almost universally lauded by critics. Its relatively unknown cast and digital age subject matter may have limited its appeal to mainstream and older audiences but if, as expected, the film becomes an awards season contender it could exhibit box office staying power.

Case 39, Paramount’s horror tale with Renee Zellweger starring for German director Christian Alvart, performed well below expectations, taking its $5.35m from 2,211 theatres (average - $2,420). The Anonymous Content production for the studio’s Paramount Vantage label opened last year in the international marketplace, taking $17m.

Let Me In, the English-language remake of acclaimed Swedish vampire tale Let The Right One In, also underperformed, with its $5.3m coming from 2,021 theatres (average - $2,622). Produced by Hammer Films and distributed domestically by Overture, the remake was directed by Matt Reeves and stars Chloe Moretz, Kodi Smit-McPhee and Richard Jenkins.

Last week’s top film, Fox’s Wall Street: Money Never Sleeps, was off 47% in its second weekend, grossing an estimated $10.1m from 3,597 theatres (average - $2,808) for a total to date of $35.9m.

Last week’s number two, Warner’s Legend of the Guardians: The Owls of Ga’Hoole, held up better, slipping only 33% to gross $10.85m from 3,575 theatres (average - $3,036) for a $30m total.

Films opening in limited release included horror thriller Chain Letter, from New Films Cinema, which managed only $143,000 from 406 theatres (average - $352); Vitagraph’s Hatchet 2, which took $62,000 from 68 theatres (average - $912); Magnolia documentary Freakonomics, which did $33,000 from 17 theatres (average - $1,941); and IFC’s French import Leaving, which arrived with $13,400 from two theatres (average - $6,700).

Next weekend’s wide releases are: Warner domestic comedy Life As We Know It, with Katherine Heigl and Josh Duhamel; Wes Craven’s 3D horror outing My Soul To Keep, from Universal; and Buena Vista’s horse racing drama Secretariat, starring Diane Lane and John Malkovich.

Estimated Top 10 North America Oct 1-3, 2010

Film (Dist) / Est wkd gross / Est total to date

1 (-) The Social Network (Sony) SPRI $23m -

2 (2) Legend Of The Guardians: The Owls of Ga’Hoole (Warner Bros) WBPI $10.8m $30m

3 (1) Wall Street: Money Never Sleeps (Fox) Fox Int’l $10.1m $35.9m

4 (3) The Town (Warner Bros) WBPI $10m $64.3m

5 (4) Easy A (Screen Gems) SPRI $7m $42.4m

6 (5) You Again (Buena Vista) WDSMPI $5.6m $16.4m

7 (-) Case 39 (Paramount) PPI/UIP/UPI $5.35m -

8 (-) Let Me In (Overture) Exclusive Films Int’l $5.3m -

9 (6) Devil (Universal) FilmNation $3.7m $27.4m

10 (8) Alpha And Omega (Lionsgate) Lionsgate $3m $19m