The other night I went to see something in London that has become an odd sensation: a woman telling other women how to speak in public.

The place was packed. At the back it was standing room only. On the stage was Viv Groskop, a stand-up comedian and executive performance coach who has written a book called How to Own the Room: Women and the Art of Brilliant Speaking.

Ms Groskop has done more than 50 events around the UK since the book was launched in November. Business breakfasts. Literary festivals. A talk for staff at Google. Another one with Facebook and two 150-seat public “masterclasses” that both sold out in days. A podcast based on the book has been a hit and later this year Ms Groskop is off to speak in Bermuda, Finland and Washington DC.