“The three-minute rule begins when the final prayer is said or song is sung.
This is not the time to talk to your best friends.
During those first three minutes, two things are going to happen: people who are familiar are going to talk to each other and people who don’t know anyone are going to leave quickly.
This is where it’s crucial.
If you take the time in those first three minutes to talk to the people who aren’t connected, you will have time afterward to talk to your friends who are more likely to stick around.
You have three critical minutes to look immediately around for people who are not connected in the body.”
Norfolk Island Church Of England 