David Letterman admitted Twitter did not interest him much. He didn’t have a lot to say, and frankly, why should he care that Justin Bieber was in a 7-Eleven, he joked during a September 2010 visit to Ball State.

But even he agreed with much of what Twitter co-founder Biz Stone said that evening about the growing reach and influence the social network has.

The late-night talk show host and social media mastermind spoke as part of the David Letterman Distinguished Professional Lecture and Workshop Series.

Stone has an extensive background as a technology industry leader. Besides Twitter, he has also founded or held top positions at several firms, small and large, including Xanga and Google Blogger.

Stone and Letterman spoke of the ever-growing force that social media has become, as well as the many highs and lows that come with starting and running a company.

Letterman asked his guest how people should cope with repeated mistakes or failure that entrepreneurs frequently experience.

“You can get an immediate reward, or you can get something else, which is you can develop character,” Stone replied. “You may not make a mistake that turns into a billion-dollar company—that’s a great mistake—but you make a series of unfortunate mistakes that lead to a buildup of integrity and character over the years. And that in and of itself is, I think, a good reward.”

To which Letterman responded, “That is exactly the right answer.”