Aji Issac, CEO, Techshu. His first venture was Idealog with 4 of his batch mates http://www.ajiissac.0catch.com/Idealog.html (started in 2nd year). He headed Grmtech for 5 years http://www.seoforclients.com/hr/grmtech-leader/. Then he headed digital marketing department at Digital Avenues Ltd.
He has given speeches on digital marketing at IIM Kolkata, Infocom, IIFT, NEN e-weeks and many more such events. You can check out some of his presentations and videos at Slideshare and Youtube.