I was surprised to hear that former First Lady and Secretary of State Hillary Clinton would be addressing a room full of marketing professionals in San Francisco this week. But that didn’t stop me and thousands of others from descending upon Moscone Center to hear what she had to say.

In her address at software company Marketo’s Marketing Nation Summit, Clinton explained how she sees digital marketing driving innovation today, and how it promotes both economic prosperity and world diplomacy.

She described herself as a champion of Internet freedom and a believer in the “transformative effect” of social media.  She talked about how she urged U.S. diplomats to use Twitter and Tumblr to communicate with citizens in foreign countries and to offer assistance to student uprisings in Iran and Egypt.

She also addressed the topic of women in leadership, particularly, the low numbers of women serving on corporate boards, in CEO roles and in top leadership positions in the United States. She admitted it was a tough problem and said that companies need to make sure they are bringing out the best in all of their employees, including young men.

Clinton drew big laughs from the audience when she described her own journey, from attorney to First Lady to Secretary of State.

“As a woman, you have to be ready to accept the fact that you are going to have some uncomfortable and maybe difficult moments from time to time. You have to grow skin like a rhinoceros.” 

You cannot take criticism personally, but you should take it seriously. You can learn from your critics. They may tell you things that friends and family never would.”

Men aren’t intentionally out to get women, Clinton told the audience. “Men are not thinking, ‘I’m going to be resistant. I’m not going to help this person. I’m going to discriminate.’ It’s very deeply rooted.”

According to her, professional women today have a difficult calculation to make:

“The messages women get coming up in the professional world are absolutely contradictory,” she said. “You are told to stand up for yourself– as my friend Sheryl Sandberg says, ‘Lean In.’ But don’t lean in too much because you don’t want to be too aggressive, too pushy, too bossy. Where do you draw the line?”

Clinton urged companies to do a better job mentoring young people– and encouraged young men and women to “find their own style, be comfortable in their own skin.”

The crowd broke into loud applause when she stated: “We can’t allow women to continue to get paid less for the same jobs than men are paid.”

The U.S. still lags behind European nations when it comes to the number of women in political positions, on corporate boards and in CEO roles.

Asked about if she would seek the Democratic nomination for president in 2016, Clinton replied, “I am honored to have people ask me and encourage me. And I am thinking about it.”

The hard questions, she said, are not, “Do you want to be president?” “Can you win?” But rather, “Why do you want to do this and what can you offer that will make a difference?”