The Twitterverse is known for generally looking down on sales and marketing messages. Likewise, when a C-level exec turns the keys to her Twitter account over to an intern, it's usually pretty obvious -- followers want genuine interaction. Those lead the reasons why Techaisle's Anurag Agrawal follows Padmasree Warrior, Cisco's CTO. "She tweets regularly and provides good information about what is happening at Cisco without being salesy," Agrawal says. He's not alone in his pick: More than 1.4 million people follow Warrior's tweets.