"At the moment, many people would feel strange about giving away, say, 10 percent of their income to fight global poverty. Talking about it may make that seem a more normal thing to do, and would encourage others to do the same."

An anecdote connected to this: I recently mentioned to some (rather well-off middle-class) people that Jewish law happens to require giving 10% if your income to charity (but the rabbis considered 20% more appropriate). It amazed me to what degree my interlocutors were provoked by the idea. Immediately they started defending themselves, their level of contribution and lifestyle, even though I didn't mean to provoke or criticize anyone.

So I fully agree - talking about the idea (and doing it!) really has an impact on people.