Be in the world but not of the world. There is a big difference. "Do not be conformed any longer to this world but be transformed..." (by the renewing of your outward actions? NO!)"... by the renewing of your mind." That means do not any longer think like the world. Marketing strategies for growing the church is thinking like the world. Targeting demographics is worldly. It is all right for businesses, but the church is not a business. When you run the church like a business, no wonder people are getting 'fired' for not conforming or 'producing' as well as the 'boss(es)' think(s) they should.
I disagree, quite strongly.
Imagine a church where the organ player simply cannot play, and doesn't seem to be able to improve. Do you "fire" them? If not, what do you do?
"Marketing strategies for growing the church is thinking like the world."
Paul had a marketing strategy. He went to major radiating cities. He went to the synagogues where he knew people were. He went only to cities that had not been evangelized. He tailored his message and method to his audience. He went back to the churches he started to make sure they were using the Word properly. That is a marketing strategy that is still in use today.