By Allison Fine

Nonprofits face a growing challenge getting their message out as Google, Facebook, and other sites increasingly try to tailor information they show to meet a person's interests.

Eli Pariser, in his new book, The Filter Bubble: What the Internet Is Hiding From You, explores these challenges, explains that as the Internet is beginning to reward things that are "likable," an article about the war in Afghanistan might not get a reader's attention, he notes.

So how does a nonprofit working on issues that might not be popular find a way to rally activists?

In this episode of Social Good, Mr. Pariser, the co-founder of Moveon.org, discusses what nonprofits need to understand about the way technology tools work and how to get round them.

Allison Fine, a nonprofit leader and expert on technology and communications, discusses how charities and foundations can more effectively use social-media tools to spread their messages and raise money. Ms. Fine incorporates suggestions and questions from readers into her podcasts and invites you to e-mail her at afine@demos.org. Look for new installments on the first Thursday of every month.