Is NFP a Hard Sell?

Is NFP a hard sell or are people open and willing to learn about it? I really find there's no one set kind of couple that I run into. Some communities in our area, Catholic communities just should project natural family planning because you're interfering with God's design. And then you have Catholic couples who have heard of it and they want to use it. Once they hear the why behind it and they understand it, engaged couples are really interested in learning this.