Here is an excerpt from Todd's blog:
David Foster writes, "Why do the people attending your church not invite other people to come to the experience? They come. They’re faithful. They give and support, but they don’t invite other people. If people in your church are not inviting people, they are not inviting people on purpose. We think they are intimidated, but they are not. They know very well how to invite people to great stuff. They do it all the time..."
So at the end of the day, maybe what you should be more focused on is helping your people love to come and to understand the benefit that others may have who come after them. Maybe people aren’t inviting people to your church because they aren’t that enthusiastic about it either.
(HT: MMI Weblog)
David is exactly correct. If someone is excited about a product or an experience, the people become natural evangelists. When people aren't inviting, one question I must ask myself immediately is, Do people that come here actually what to be here themselves? I may not like the answer, but I have to be willing to ask the question.