Twitter is rapidly changing the way nonprofits promote their causes and connect to supporters, creating new opportunities—and challenges.

In her forthcoming book, Twitter for Good: Change the World One Tweet at a Time (Jossey-Bass), Claire Diaz Ortiz, Twitter’s top official in charge of working with nonprofits and corporations on social innovation, provides advice on how charities can best use Twitter to produce tangible results.

Following is a transcript of an interview with Ms. Diaz Ortiz conducted via Twitter about how nonprofits can use the service to promote their causes.