I think it's Bill Hybels who I heard ask the question, "Who's the competition for your church?" After letting us think about it for a little while, he said that other churches in your community may have come to mind, but that would be wrong. Other churches are on the same team, they're not the competition. The competition is anything that draws people away from God and away from the church.
The pastor of one of the larger churches in our community told me that when they were looking for land, they considered land close to us, but felt they should keep their distance from other churches. I told him he didn't need to do that for us because we don't see his church as the competition. Anyway, they are quite different in style, meaning we don't normally reach the same folks.
Recently I heard a rumor that the largest church in MN (whose style is much like ours) was considering starting a campus in Woodbury. (It may be more than a rumor, I really don't know.) I had to gulp hard on that one and remind myself that we're on the same team and that most churches reach folks through personal invitation (meaning that most of the people we reach, only we can reach, and vice versa). That one really tested my conviction. I really don't think of other churches as the competition.
But there is at least one good thing about thinking of another church as competition. When a highly effective church is moving into your community with a new campus, using a multi-site approach, the church that feels threatened just might get it's act together, even if it's for survival. Maybe, just maybe, they'll stop arguing about music styles or color of carpets or how the youth dress when they come to church. Maybe they'll start thinking about bringing lives to Christ (i.e., making more disciples) as much as they think about bringing Christ to everyday life (i.e., making better disciples). Maybe the "competition" will help them get in the game. This is the idea explored "The Walmart Factor for Churches."