On Pete Blackshaw's first tour of duty with a major marketer -- Procter & Gamble Co. in the late 1990s -- he made his first try at launching an internal social network. That was before marketers, like everyone else, were schooled in the art of social networking, and it didn't catch on then, as Mr. Blackshaw remembers it.

Now as global head of digital and social media at Nestle since 2011, Mr. Blackshaw has given it another try with much better results. Nestle's internal social network is part of his effort to "rapidly scale knowledge" at the far-flung food giant, with global sales of around $100 billion and 200,000 employees on its internal social network. Mr. Blackshaw is happy with the amount of activity on the network from senior executives on down.

In a video interview during the first day of the Ad Age Digital Conference, on April 1, Mr. Blackshaw discussed why having an internal social network is important. "If we want to lead digital, we need to practice digital internally," he said. The network is also part of his effort to spread the word internally about the dozen digital startups Nestle works with at its Silicon Valley outpost.