Do Young People Understand the Power of Prayer?

In my role with SIM I run a prayer night once a month at my home in which young people are invited to come along and pray for missionaries. I don't try to 'jazz it up and make it sound youthy' because I believe that if young people are serious they shouldn't need the frills.
I've found it constantly difficult to get young people/adults to come along. There are always other reasons why not to, sometimes quite legitimate ones (who am I to judge?) but I wonder whether young people really understand the power of praying. In March I had 8 come along, I was thrilled. April no one came at all. This month we've split in two, one north of the river and one south. I had one come to mine and I'm hoping the rest of them went to the north one.
Anyone got any suggestions in drawing young people in to come along?