In a venue that 's seen its share of sales pitches over time, the Association of National Advertisers convention in Phoenix got what may have been its most quietly audacious ever from Facebook Chief Operating Officer Sheryl Sandberg on Saturday morning.

Ms. Sandberg's message: Facebook shouldn't be the only thing marketers do online or in marketing. It should just be part of everything they do.

"Social by design" was her fundamental takeaway for marketers, echoing what's fast becoming the pre-eminent marketing catch phrase of 2011, and standing for a strategy in which the glue that holds together marketing plan is designing all elements to amplify or be amplified by social media. And while the phrase sounds suitably unbranded for a general-session presentation, the reality is that given the position of Ms. Sandberg's company as the by -far dominant social medium, her notion translates readily into "Facebook by design."

Ms. Sandberg prefaced her pitch with a brief history of the web, including the famous 1992 "On the internet, no one knows you're a dog" cartoon from the New Yorker. Of course, thanks to Facebook, now everyone knows you're a dog, and, depending upon how well you manage privacy settings or how actively you engage brands, they may also know your favorite kibble and when you've been drinking out of the toilet.

For Facebook not only is overall sharing doubling every year via "Zuckerberg's Law," she noted, but the number of daily fan page "likes" also has doubled in the past year to 100 million daily.

"If you look at the numbers for almost any brand, but certainly any brand that 's invested any time or effort on Facebook, the number of people who are your Facebook friends massively dwarfs the number of people who visit your website," Ms. Sandberg said. "So I think one of the questions this industry needs to ask itself is why? Why continue to build as many microsites as we do when we know it's so much easier to reach people where they already are?"

She added that , "We are big supporters of everything you do online and think you should be doing more not less." But she noted that "other ads only talk one way," whereas operating within Facebook with "for the first time, real identity, real relationships, real personalization, marketing can really fulfill its promise."

Citing data from Nielsen, a relationship Ms. Sandberg said she developed on the advice of Sony Pictures Entertainment Chairman-CEO Michael Lynton, she said Facebook significantly outperforms other online media for reach either against narrow or broad targets, thanks in part to the friends-of -friends effect.

She also delivered what many marketers have found lacking from their early social-media efforts -- case studies with hard numbers showing sales lift from Facebook-centered programs.

American Express's "Small Business Saturday " program following last November's Black Friday, using Facebook at its core but also executed through other local media such as newspaper advertising, produced a 28% sales lift vs. 9% year over year for retailers overall that day, she said.

A Hong Kong-based "social by design" campaign for Kimberly-Clark Corp.'s Huggies got people to upload their baby photos to the brand's fan page, then placed those photos in montages on bus and subway ads. The result, Ms. Sandberg said, was a 4.2% increase in market share and "by far the best quarter in Huggies' Hong Kong history."

"We aren't arguing you shouldn't keep doing what you've been doing" in other media, Ms. Sandberg said. "But you should think about social as an absolutely fundamental ingredient."