Different Countries and cultures express faith differently, although evangelism is not for me (especially TV evangelism) it obviously works for them.
Faith is a funny thing Pilsudski locked himself away from everyone as part of the national novena before the battle of Warsaw.
His plans that formulated out of this became known as the miracle on the Vistula, what place did faith and prayer muster in this instance, every able bodied man called up to fight and 100,000 women, children and old men marched forth in prayer, hope and desperation. It unified the people.
Slightly off thread I know but the point I'm trying to make is faith brings many people happiness, and the sermons they see on these channels make them happy which is why they fund it.
Similarly people who watch "Big Brother" (another mystery to me) phone in with their numerous votes, without it the show would be off air in a shot.
To each their own.