Hartford Seminary has been researching church growth, and it has discovered that they stereotype most of us carry that all church growth is happening in very conservative, very big, very suburban churches isn't accurate.
Many downtown churches grow, especially if they find themselves in re-developing areas of the city.
Growing churches have found ways to attract more men, (another hot topic in religious journalism these days) they have a website, they use percussion in worship services, have a recruiting plan, and offer support groups and wellness programs. Theologically liberal churches grew more than conservative, and "somewhat conservative" churches grew more than "predominately conservative."
A major finding: Growing churches tend to be multi-cultural and nothing kills growth as effectively as a church conflict.
Why are growing churches multi-cultural? Aside from the longing many religious people have to live out their values in a multi-cultural church, insofar as growing churches attract persons under 50, persons under 50 are far more multi-cultural and far more comfortable with diversity than their elders.
The two strategies which seem to have brought growth (and diversity) in this congregation have been helping the Young Adults get organized and starting a specialized "extended family" (yep, we still have them from the 1970's...they are long term social/support groups) for multi-racial/multi cultural families.
You can see the whole report here