We don't really do any advertising. Most of the people that start coming are referrals from current members. The church has a large home/premise school program that draws in a lot of people and that spills over to the church side. Also, we have a dedicated youth minister that actually tries to respond to people reaching out.
Recently the local Presbyterian organization at a large university reached out to 6 local Presbyterian churches (of three different denominations) to see if they could host a weekly group of about 15 university students on Sunday....our church was the only one that responded. We now have 15 college age people attending on Sunday that were not there before.
I think that to many churches are too passive about reaching out in person, or via phone to people new to the neighborhood. Also keeping in touch with members that have not showed up for a while. The church I was a member at before now has never reached out to me in the last year, and I was very active - and they need members. The RCC parish I was a member at for 10 years never reached out when I left, and I was active in KOC and went to every Sunday and Holy Day service.
Simply sending an email or making a call would really go a long way for a lot of churches.