Wi-Fii by Kristin Marshall on Flickr. Some rights reserved.
So claims well-known evangelism expert – er – Andrew Lloyd-Webber. Read more here.
Does he have a point?
Wi-Fi Your Church To Put It At The Centre Of The Community
Thinking About Mission
Resources to promote thinking and action about Christian mission in the local church
Thinking About Mission 
Not really.
Wi-Fi might entice more people to come into the building when it’s open, say for coffee shops, or even a Sunday service. But unless they can see the difference that our faith is making in our lives, it’s unlikely they will want to stay, hear the Gospel and be part of our faith community. Like the new couple who came to a Sunday service a few years ago, were shouted at for sitting in someone’s (own personal!) seat, turned round and walked out. They’ve never been back.
Having Wi-Fi wouldn’t fix that problem; it’d be like trying to get a broken down car to start by painting it a different colour.