I believe the most important aspect of being a church that reaches a lot of unchurched people is creating a culture of evangelism. The only way I know to create a culture of evangelism is to preach the Gospel every week.
We give people an opportunity to come to know Jesus in our services every week and not a week goes by when we see people give their lives to Jesus.
You have to preach on evangelism, but people need to see the Gospel preached and see people respond.
It builds people's faith when people are turning to Jesus every week they come to church. When they see other coming to Jesus every week in the services, they think, "If I invite my friend, family member, or neighbor, they may come to know Jesus here as well."
Of course, this can't replace personal evangelism, but it compliments personal evangelism nicely.