Coke's Clark (left) and me at the Fortune MPW Summit

In social media, Coke is it. Coca-Cola is the biggest consumer brand on Facebook (FB). At the Fortune Most Powerful Women Summit earlier this month, I interviewed Wendy Clark, SVP of  Integrated Marketing Communications and Capabilities at Coca-Cola (KO). The day before we hit the stage, Clark sent me an email to share her ideas. That email, which she wrote on the plane on her way to southern California, was so helpful and so smart that yesterday, after Coke reported its quarterly earnings, I pinged her to ask if she would let me share it with you. She graciously agreed. So here are Wendy Clark's seven rules for building a mega-brand in social media:

1. Be share-worthy in everything you do.

In a market that is now completely socially connected, we increasingly are thinking about our audience in two ways: our Initial Audience--those we can reach directly (52 MM Facebook fans, 600k Twitter followers, 18MM My Coke rewards members, etc)--and our Ultimate Audience, which is those people whom our Initial Audience can reach for us. For Coca-Cola, our Facebook fans are just over one fan or friend away from the entire Facebook community of 1 billion+. So if we do our job well of developing useful, compelling, interesting and share-worthy content, our fans become our sales force for us.

2. Listen. Then respond authentically and humanly.

The days of hiding behind two-sentence corporate statements have to end. This is easier said than done. We're still unlearning this. Consumers and all constituents expect more. Coca-Cola isn't a faceless corporation to them; it's a brand they love and enjoy throughout their day. So when they interact with us, they expect that same experience: a human interaction. There are more than 15,000 Tweets everyday on brand Coca-Cola; any that are a question, we answer. We have to. Consumers' expectations are that we're listening and responding.

3. Think big. Start small. Scale fast.

If you have an ambition that you want to double the size of your business in, say, 10 years, you had better have a big innovation pipeline to help get you there. When we're at our best, we think massively, but we beta and test that thinking in small bets to learn. To meet our innovation (and growth) ambitions, we are trying to get much better at discussing failures or learnings. For a big company like ours, it's critical. Because we're built for scale and if we don't get better at testing, learning and then scaling, we have the potential of scaling the wrong thing perfectly.

4. Social is not a silver bullet. But social can make everything else better.

So much is made of social media and marketing that we can tend to overrate what it can do. We do not see social marketing as a standalone. Rather, our mantra for our media and connections planning is "social at the heart." So we think in terms of ideas and campaigns that are social (share-worthy) at their core and then we think about how we can amplify the ideas and campaigns. Too often, we get asked if our TV investment is declining and our social/digital investment growing.  This is the wrong question. It's not an EITHER, it's an AND.

5. Content is the new currency. Create accordingly.

With 72 hours of content uploaded every minute on YouTube (GOOG), the world is not suffering from lack of content. With this in mind, content creation has to be useful, interesting, important, share-worthy. We learned this in seeing the difference in interaction level between status updates and Tweets that we wrote vs. those that our agencies wrote. We also learned that replication isn't always a good thing in social marketing.  When we had a hit viral video in Coca-Cola Happiness machine, our first instinct was to replicate the film. We did that and had a fraction of the views.

6. We might be shepherds, stewards and guardians of our brands, but we no longer control them.

At best, we get to participate and co-create with our fans. I'd estimate that 10-20% of the content and conversation on our brands comes from us. The other 80%+ comes from others. So we need to get invited in to these communities and co-create with our fans.

7. Think of your constituents as storytellers.

Taking the principle of Initial and Ultimate audiences, we're increasingly thinking about all of our constituents as storytellers, not just receivers of our content. This includes our consumers, employees, NGO partners, media, etc.. So our principle becomes that we create content and tell stories that we want to be retold.

Here's a clip from my interview with Clark: