Church Planting in general is a fairly new phenomenon.
A new approach of church planting is planting missionally. I think there are a few fundamental shifts in how to launch that those who want to plant missionally need to process.
1. Market Mission not Celebration (If you market)
Some missional practitioners will say not to market at all. I am inclined to agree with them in large part. If you do the right things, the market will find you. You won't need to find the market.
But starting an organic movement from the ground up could make you the best kept secret in your city, which isn't beneficial either.
The place I'd land is to market mission rather than your "launch Sunday".
Often the move toward Launch Sunday causes the church to do mission/outreach/marketing to advertise and convince people to come to that first Sunday.
Sending mailers to advertise your first church service will eliminate the majority of people in your community who are not interested in church to begin with.
But raise awareness about the move the address hunger in your city with a big feeding event? Or send a mailer about a new initiative to raise the stakes in education for your community? People will join you in that cause because hunger and poor education systems are unacceptable (especially in their city...where their kids go...where their neighbors may be the ones who are hungry.) Relationship and Cause trump your Sunday morning experience. Foster relationship and rapport with your city by doing things that give life to the city.
We launched C3 by getting three communities in place and then as we moved to gathering those communities for Celebration, we had an event where we packaged 20,000 meals for Columbus in 2 hours. We had between 250 and 300 people at the event...and held it during church services so Christians from other churches wouldn't come (sounds terrible, but we don't want disgruntled church people. We want the spiritually hungry/restless folks.)
2. Think Low Cost and High Relationship
The driving question for the missional church planter when it comes to budget/funding is "Could we spend this money in better ways to give life to our city?" Yes we could have the more epic sound system and signage...but at what cost? Sure we could rent the movie theatre for our gathering space. The average cost for theatre rental for churches is somewhere around $900 a week. Around $50,000 a year. It's a sexy space, but the question is do you sacrifice your heart and DNA as a movement for the sake of being sexy? (Gaining the world and losing the soul kinds of things).
I would take a school for $450 a week over a theatre every day of my life in the missional church planting context. Why? Because the relational equity that can be gained through relationship with a school is far greater than that which can be gained in a movie theatre. And that move frees up $25,000 annually to bless the school and the city in more tangible ways.
Sustainability is a question mark for critics of the missional model. And some of that critique is legitimate...Because missional plants are trying to insert their heart and DNA into a traditional approach to church planting.
If Cause and Community (Missional Communities!) are the driving force of your DNA, show it in your budget. The typical "attractional" church spends between 80 and 90% of their budget on their building/Sunday morning experience. Don't say you're a missional church plant if the same is true for your church. It's not criticizing the model...there is value for sure in drawing people to gather...but Cause and Community take a backseat in this model. For me, ministering in a 20-something context in the city...cause and community can't take a back seat.
3. Think Leadership Development instead of Hole Filling
Yes you have lots of holes to fill to do this thing well, but your primary task as the leader of a missional movement is to model the way intentionally for potential leaders to follow your lead. Live a life that is imitable as you imitate Christ and let replication happen. Decentralized leadership is the absolute key to missional church planting success. Without replication of leadership you will only be able to lead 50-60 people before your own leadership equity dries up...You will plateau and you will either switch models to try to grow or you will be satisfied leading something that you can "manage" on your own. You can either breathe over the movement in hope it grows or you can breathe over individuals and watch it grow. The latter is a better way, prevents burnout, prevents you from doing it in your own strength and by your own charisma and equips the saints for the work they're designed to do!