"It's a nice thing to use social media to get it out. This is a step in the right direction," Ogunmola said. "But the point is to actually find the girls."
All told, police say, more than 300 girls were abducted from their secondary school in the country's remote northeast, and 276 remain in captivity. Though details of the abductions have been public since they were carried out, the case was not widely followed until (hash)BringBackOurGirls and other hashtags attracted a torrent of attention.
More than 2.1 million tweets using (hash)BringBackOurGirls have been posted, according to Topsy, a site that offers Twitter analytics. Interest was relatively low until last week, when celebrities including singer Chris Brown sent messages that were widely circulated.
More than 380,000 tweets carried the hashtag Wednesday, including one from Michelle Obama, who has been retweeted more than 53,000 times. Use continued to grow Thursday and Friday.
"We have discovered the power of the hashtag," said Nigerian author Chibundu Onuzo, writing in The Guardian.
The flurry of attention on Nigeria brings to mind a similar campaign two years ago that introduced many people to Joseph Kony, a guerrilla leader whose group has abducted many Ugandan children who then became sex slaves or fighters. A video about Kony went viral in 2012, but public attention waned, and the warlord remains at large.
G. Nelson Bass III, a professor who teaches politics and international relations at Nova Southeastern University in Fort Lauderdale, Florida, said the (hash)BringBackOurGirls campaign appears far closer to the Kony campaign than to the kind of social media activity that organized much of the Arab Spring movement.
In the former case, public awareness widened but never resulted in any particular action, unlike in the Middle East, where social media were used to coordinate protests.
"At its current moment, I fear this campaign lacks the information to do much more than educate," he said.
The acclaimed Nigerian-American author Teju Cole, writing for The New Yorker, called the abductions Twitter's "cause of the day." Writing on Twitter, he suggested the hashtag campaign was accomplishing little, saying: "For four years, Nigerians have tried to understand these homicidal monsters. Your new interest (thanks) simplifies nothing, solves nothing."
Boko Haram, the Islamist extremist group responsible for the kidnappings, did not enter Google's top search terms until Monday. And a search of the LexisNexis news database found 3,445 English-language stories mentioning that group in the first four days of this week, more than the previous 18 days combined.
Gordon Coonfield, a Villanova University professor who studies new media, said the story of the Nigerian girls is following a familiar arc, in which interest is ignited and then quickly dissipates.
The drama presents an opportunity to the masses to casually adopt the hashtag as their cause: "People can care so fiercely at this moment only on the condition that they can completely forget about it tomorrow," he said.
"Social media won't find them," he said, but it could fuel broader discussions on injustice and what led to the kidnappings. "This will happen only if we can sustain a network of attention longer than 140 characters."
Follow Matt Sedensky on Twitter at http://twitter.com/sedensky .