I don't know anything about Kenneth Copeland's mega church. I am surprised that it would be all that large seeing as how everyone I have ever met can't stand him.
I know that Lakewood Church (whatever it's called) bought an entire football stadium to seat all the people. And I think that is pretty awesome. I have heard Joel Osteen a handful of times going back many many years. Each time I have heard him preach it sounded exactly like the last sermon I heard even if it was 10 years since I last listened to him. That being said, I personally never heard him say anything that was false teaching or crazy talk that I have heard everyone say that he teaches. I am not saying he does not teach crazy talk maybe he does, I am just saying when I have listened to him it was always about things like, "If someone is giving you a hard time at work because you are a christian, don't let it get to your peace, just keep being kind and loving and focus on Jesus and pleasing him and God will give you victory in your work place and even if they fire you, God will give you a better job because you keep him first" Things like that. And those kinds of messages are actually needed when you realize how many Christian wives come home and complain to their husbands all evening about who mistreated them at work. So I really can't knock him for preaching these messages even if people think he is too "postive" or "word of faith" I don't think he is an extreme like Kenneth Copeland.
Now that I said that. I think it is awesome that an entire football stadium is packed full of people hearing about Loving Jesus and keeping their focus on pleasing God in the face of adversity don't you? Amen, I knew you would.
I wish all the football stadiums were filled with people wanting to please Jesus with their whole heart.