Back when Zuckerberg was a but a tween and Twitter was yet a twinkle in anyone’s eye, the customer of a multivariate testing SaaS vendor ran an interesting promotional test: 20% off any purchase against buy one refrigerator and get another free. To everyone’s surprise, refrigerators flew out the door. Turns out, the Joneses found out about the deal and told the Smiths who came in on it with them. Each family went home with a half price fridge.

What a testament to the power of testing, we all said. Who knew you could move such a large item with such a promotion? What we all thought we learned was that you never know what you don’t know. And you’ll never know unless you test.

Facebook's arrival as a lifestyle brand was cemented the moment Zuckerberg appeared on Oprah. Having been on Facebook for several years as an Internet marketing professional, one can't help but notice the sudden barrage of old high school friends (stay at home moms) having suddenly found me on Facebook. A noticeable shift in the FB demographic has taken place in the last six months.

Which makes the brand now part of popular culture, properly cited by Steve Rubel as the key motivation for recent advertiser interest in Facebook. Advertisers from Palm to Sprint are plugging Facebook in TV spots, aligning themselves with the social media icon that touches 200 million everyday.

What a week it's been for our little blue friend. Everywhere I look, all my favorite sites and blogs are bashing the poor creature. Admittedly, I've done a bit of Twitter bashing myself (although I prefer to think of it as critical thought).

Like what Mitch Joel has to say about the inherent "volume contradiction" in all social media. Once the volume of any given network (your Facebook friends or Twitter followers) gets to significant levels, the network is no longer "social". (Check out what I had to say about that a few months ago in 'Twas the Night Before Twitter Got Monetized.) What may have once been a set of one-to-one interactions by necessity becomes a series of one-to-many broadcasts.

And as a communications channel for would-be marketers, how is that any different from, say, display advertising - also a one-to-many broadcast model?

I've been wondering what the Twitter value proposition to me is for some time. I get what Twitter is, and yes, I Tweet, but I've never been entirely sure why Twitter should matter to me. Apparently, many share in my quandry, says Silicon Valley, The Harvard Business Review, Nielsen and others.

By a number of measures, Twitter's metrics look pretty dismal. User engagement is low and customer retention even lower. Numbers like these beg the question, what is the real and compelling value to a business or consumer in using the Twitter application?

Even the CEO says what he's shooting for in a relationship with his audience is addiction.