Sheryl Sandberg’s Lean In: Women, Work and the Will to Lead seems to be a book for women only.

Maybe it’s not.

New York Mayor Mike Bloomberg and JPMorgan Chase Jamie Dimon threw book-promo bashes for Sandberg this past week.

This morning, I met with Sandberg and American Express CEO Ken Chenault—another male master of the universe whom the Facebook COO has captured on her Lean In bandwagon.

Maybe it’s feminist guys who have helped push Lean In, released on Monday, to the pinnacle of publishing: Her book is No. 1 on .

Next week I’ll share clips of my conversation with Chenault and Sandberg. Meantime, here’s Sandberg talking about a fresh and critical component of her crusade: her Lean in message to men.