“She was promoting her new book.”

You went to a talk given by a business book author last night. You are telling your friend about the event and the speaker. You explain why she gave the talk by saying:

She was promoting her new book.

promote (something)

To "promote" a creative work means to do things like talks, radio interviews, press conferences, and book signings in order to tell more people about your work. Things that people "promote" include:

promote your book

promote a movie

promote your new album