Three weeks after itspremiere, "Sharknado" is still raining down great whites andhammerheads for the U.S. cable television network Syfy - andeven splashing them across movie screens.

The campy, low-budget TV disaster movie about a hurricanethat unleashes an aerial shark attack on Los Angeles has proventhat a B-movie can still be a big cult winner, especially whensocial media acts as its marketing machine.

"You can't replicate something like this, you can'tforce-feed it - it just sort of happens," director Anthony C.Ferrante said ahead of special midnight "Sharknado" showings in200 U.S. theaters on Friday.

Syfy already has ordered a "Sharknado" sequel and althoughthe film is not yet a month old, it is drawing comparisons to"The Rocky Horror Picture Show," the 1975 cult classic that hasmade its mark as a midnight feature.

"Sharknado's" debut on July 11 drew an audience of about 1.4million - slightly under Syfy's average for made-for-TV films -but it generated a significant 5,000 tweets per minute at itspeak.

Top-shelf tweeters included "Rosemary's Baby" actress MiaFarrow, "The King of Queens" actor Patton Oswalt and "30 Rock"actor Judah Friedlander, who each enjoy large Twitterfollowings.

"The irony is that I thought we'd probably get the horrorfans but the best we could hope for is the midnight cultfollowing just because it was so strange and then it blew up,"Ferrante said.

The film, which stars former B-list actors Ian Ziering andTara Reid, has its lead characters attempt to save Los Angelesfrom "sharknados" with chainsaws and bombs as the killer fisheat their friends and destroy landmarks such as the Hollywoodsign.

"Sharknado" also has attracted larger audiences in subsequent re-broadcasts, including 1.9 million on July 18 and2.1 million on July 27.

'THIS GENERATION'S ROCKY HORROR'

"What is unusual is to have the second airing (with) more(viewers) than the first," said Horizon Media analyst BradAdgate. "That never happens to that extent - 2.1 million isn'tsomething that an original movie can do on Syfy."

Syfy, a unit of NBC Universal's Comcast Corp,produces about 20 films annually, including titles such as"Dinocroc vs. Supergator" and "Piranhaconda," at about $1.5million per film.

Although "Sharknado" might not add much to Syfy's bottomline aside from some DVD sales and on-demand Internet streaming,it has been a publicity coup for the network, Adgate said.

"It put them in the mindset of viewers for what kind ofmovies they put on, this tongue-in-cheek, hokey type of movies,"he said.

"It started in social media but it was also in themainstream media. That's what really propelled it to become acult classic. Maybe it's this generation's 'Rocky Horror PictureShow.'"

"Sharknado" was tailor-made bait for Twitter and Facebookwith its zany premise and so-bad-it's-good special effects,social media analyst Carri Bugbee said.

"People naturally want to talk about and riff on things thatare internet memes and cultural touch points, like movies,music, and TV," Bugbee said.

"If you create something wacky and outrageous it givesanybody an opportunity to say something funny to entertain theirfriends," she said. "I sort of see it as a natural extension ofsomething we saw in the past with 'Rocky Horror Picture Show.'"

That low-budget cult film has grossed more than $100 millionat U.S. theaters over nearly four decades.