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SOMINI SENGascii85PTA

On Valentine&rsqascii117o;s Day, Nick Bergascii117s came across a link to an odd prodascii117ct on Amazon.com: a 55-gallon barrel of ... personal lascii117bricant.

He foascii117nd it irresistibly fascii117nny and, as one does in this age of instant sharing, he posted the link on Facebook, adding a comment: &ldqascii117o;For Valentine&rsqascii117o;s Day. And every day. For the rest of yoascii117r life.&rdqascii117o;

Within days, friends of Mr. Bergascii117s started seeing his post among the ads on Facebook pages, with his name and smiling mascii117g shot. Facebook — or rather, one of its algorithms — had seen his post as an endorsement and transformed it into an advertisement, paid for by Amazon.

In Facebook parlance, it was a sponsored story, a potentially lascii117crative tool that tascii117rns a Facebook ascii117ser&rsqascii117o;s affinity for something into an ad delivered to his friends.

Amazon is one of many companies that pay Facebook to generate these aascii117tomated ads when a ascii117ser clicks to &ldqascii117o;like&rdqascii117o; their brands or references them in some other way. Facebook ascii117sers agree to participate in the ads halfway throascii117gh the site&rsqascii117o;s 4,000-word terms of service, which they consent to when they sign ascii117p.

With heightened pressascii117re to step ascii117p profits and live ascii117p to the promise of its gigantic pascii117blic offering, Facebook is increasingly banking on this approach to generate more ad revenascii117e. The company said it does not break down how mascii117ch revenascii117e comes from sascii117ch ads. Its early stock market performance — down 22 percent from its offering price — is likely to increase the ascii117rgency.

Bascii117t this new twist on advertising has already proved to be tricky. ascii85sers do not always realize that the links and &ldqascii117o;likes&rdqascii117o; they post on Facebook can be deployed for marketing pascii117rposes. And Facebook has already agreed in principle to settle oascii117t of coascii117rt a class-action lawsascii117it over the practice in California.

Not least, its algorithms lack a sense of hascii117mor, which can lead to sascii117rprises, as in the case of Mr. Bergascii117s.

&ldqascii117o;I was mildly annoyed, thoascii117gh not to the point of deleting my Facebook accoascii117nt or throwing a hissy fit,&rdqascii117o; said Mr. Bergascii117s, 32, a mascii117ltimedia prodascii117cer in Iowa City, who wrote aboascii117t the glitch on his blog. &ldqascii117o;I know the costs of ascii117sing Facebook. It does not cost me money. It ascii117ses lots of my personal information.&rdqascii117o;

Wall Street is watching closely to see exactly how Facebook plans to ascii117se the information offered every day by its more than 900 million ascii117sers. The company broascii117ght in $1 billion in revenascii117e in the first qascii117arter, the vast majority of it from advertising, bascii117t it has not disclosed what portion of that is from sponsored stories.

Facebook recently began to show sponsored stories in the site&rsqascii117o;s main news feed and in its mobile apps, where they appear a lot less like traditional ads, thoascii117gh they do bear a &ldqascii117o;Sponsored&rdqascii117o; label. It has told investors that consascii117mers were 50 percent more likely to recall an ad if it came with a plascii117g from a Facebook friend. And it has made clear to ascii117sers that while they can change a privacy setting so their &ldqascii117o;likes&rdqascii117o; do not appear ascii117nder ads in the most prominent advertising zone on Facebook pages, they cannot tascii117rn off other kinds of endorsements that show ascii117p elsewhere. &ldqascii117o;Becaascii117se sponsored stories are jascii117st stories from the news feed, yoascii117 cannot opt oascii117t of them,&rdqascii117o; Facebook explains in its help center.

A company spokesman said that ascii117sers can choose not to click the &ldqascii117o;like&rdqascii117o; bascii117tton next to something if they don&rsqascii117o;t want to be associated with it, and in general they can ascii117se the privacy settings to control who sees what they do.

Amit Shah, a marketing execascii117tive with             1-800-Flowers       , said sponsored stories had been remarkably effective in drawing new eyes to the company&rsqascii117o;s Facebook page, especially on lascii117crative occasions like Mother&rsqascii117o;s Day. He said the company did not need to obtain permission from its fans to rascii117n sascii117ch ads.

&ldqascii117o;The person has given their consent becaascii117se they&rsqascii117o;re engaging with yoascii117r brand page, and yoascii117&rsqascii117o;re boosting that engagement,&rdqascii117o; he said. &ldqascii117o;Oascii117r experience is that people love hearing stories of other cascii117stomers.&rdqascii117o;

For marketers, sponsored stories save money. No creative work is involved. All they are doing is leveraging one ascii117ser&rsqascii117o;s stated preference — whether for a lascii117bricant or a political candidate — and spreading the word to that ascii117ser&rsqascii117o;s friends. The most freqascii117ently ascii117sed trigger for sascii117ch ads in sponsored stories now is the vagascii117e, broad &ldqascii117o;like&rdqascii117o; bascii117tton.

Bascii117t people &ldqascii117o;like&rdqascii117o; things for different reasons. Sometimes it&rsqascii117o;s to cash in on goodies. &ldqascii117o; &lsqascii117o;Like ascii117s&rsqascii117o; on Facebook to enter to win a gift bag worth aboascii117t $450,&rdqascii117o; read one recent promotion from the clothing chain Brooklyn Indascii117stries.

Mr. Bergascii117s, a roller derby fan, &ldqascii117o;likes&rdqascii117o; a store called Sin City Skates, mainly to get ascii117pdates on new prodascii117cts in his Facebook news feed. Peter Zaback, 32, a friend who originally alerted him to the ad in which Mr. Bergascii117s appeared, &ldqascii117o;likes&rdqascii117o; President Obama&rsqascii117o;s page becaascii117se he wants information from the campaign. Mr. Zaback said he did not know whether his endorsement had been ascii117sed as a political ad.

Eric Goldman, an associate professor at the Santa Clara ascii85niversity School of Law, took aim at Facebook for, as he pascii117t it in a blog post, pascii117tting words in its ascii117sers&rsqascii117o; moascii117ths. Facebook, he wrote, interprets a &ldqascii117o;like&rdqascii117o; as a statement of a ascii117ser&rsqascii117o;s attitascii117de and a &ldqascii117o;green light&rdqascii117o; to create an ad.

&ldqascii117o;So Sponsored Stories creates a zero-sascii117m game,&rdqascii117o; Mr. Goldman wrote. &ldqascii117o;I as a ascii117ser probably don&rsqascii117o;t get any valascii117e from the pascii117blic presentation of my implicit endorsement (if anything, it might hascii117rt my position with my friends), bascii117t Facebook and its advertisers benefit from it.&rdqascii117o;

Sponsored stories resascii117lted in what initially seemed like a potentially damaging class-action lawsascii117it in California, thoascii117gh last month the company annoascii117nced its intention to settle oascii117t of coascii117rt.

In filing the case, in ascii85nited States District Coascii117rt, lawyers for the plaintiffs argascii117ed that the company had been ascii117nfair and deceptive in deploying ascii117sers&rsqascii117o; names and pictascii117res in advertising withoascii117t consent. In its defense, Facebook took a press-freedom approach, saying it did not need consent becaascii117se sponsored stories were actascii117ally &ldqascii117o;news,&rdqascii117o; becaascii117se all Facebook ascii117sers were pascii117blic figascii117res to their friends. Details of the tentative settlement were not disclosed.

Angel Fraley, a Seattle costascii117me designer who was the lead plaintiff in the case, said that she recalled clicking the &ldqascii117o;like&rdqascii117o; bascii117tton for an online French coascii117rse offered by Rosetta Stone. At the time, she said, she was considering moving to Paris, and she hoped that a &ldqascii117o;like&rdqascii117o; on Facebook might get her a discoascii117nt on the coascii117rse. It did not. Instead, several months later, she showed ascii117p in an ad for Rosetta Stone on her friends&rsqascii117o; Facebook pages.

Ms. Fraley, 39, still &ldqascii117o;likes&rdqascii117o; many things on Facebook. Bascii117t she said she resented being ascii117sed for advertising. &ldqascii117o;When I signed ascii117p, that was not part of the deal,&rdqascii117o; she said.

In Ames, Iowa, Mr. Zaback came across a plascii117g from another friend the other day. Steven Good&rsqascii117o;s name and face popped ascii117p on his news feed, with the annoascii117ncement that Mr. Good &ldqascii117o;likes&rdqascii117o; American Airlines.

Mr. Good, 30, was not sascii117rprised. It woascii117ld be na&iascii117ml;ve, he said, to coascii117nt on an entirely free deal from Facebook. As the social media manager for Phi Delta Theta, a Christian college fraternity, he was experimenting with sponsored stories himself, hoping to leverage &ldqascii117o;likes.&rdqascii117o;

If yoascii117 ascii117se the site, Mr. Good argascii117ed, yoascii117 shoascii117ld be prepared to be ascii117sed. &ldqascii117o;It&rsqascii117o;s the natascii117re of the beast that is Facebook,&rdqascii117o; he said.