Distinguish between a Visitor and a Potential Member. This is true whether the person returns two weeks in a row or twice in six months. A second visit demonstrates serious interest in your congregation. It is more important to worry about how to track and follow up with potential members than how to advertise for first time visitors. Most people decide within 5 minutes of arriving in the parking lot whether or not to return a second time.
Most visitors arrive within five minutes of the advertised starting time.
Avoid blocking the doors just before the service with the choir or processional lines. Many churches have learned the wisdom of having the clergy present at the main entry just before the service begins. Most churches still follow the unfortunate practice of having male ushers who also function as the greeters. Just as at home, it is better for you and your members to introduce visitors than for them to have to do it themselves. First, introduce them to at least 3 other members.