well no but in mega churches it seems there are more likely non christians going there.
Because the mega church does an altar call every single week, and they have three services a day, and everytime I have been they did one.
discipleship is ongoing and we always affirm we are christians by praying together, reading scripture, participating in the lords supper.
Evangelism is more effective outside the church, that is where the lost are. It may be yes they are ready to start going to church to fellowship but most of the time people are converted outside of it, God reaches out to where they are and draws them in, its not likely unbelievers would think of just going to church, the only time they would go is if someone asked them for social reasons or food or some other reason and not really for Jesus. If someone does come and you discern they are ready you can tell them the gospel and pray to receive the holy spirit, but, usually its a more one on one and its not 'all you sinners come to the front!'