Meta humor works because our reaction of "I knew that was coming and it only made me laugh more" is our reality. I see this in both my children (a 2 year old and an 8 month old) when I'm repeating something silly to get a laugh. They anticipate a reaction/laugh to the point they begin laughing before I've done "The (fill in the blank)" again.
I enjoy this brand of comedy. Maybe that makes me a little dull. Personally I can't stand most modern comedies. They always explain the punchline as soon as it's delivered. You don't have to tell someone it's funny to make it funny. This might be another reason they are so easily parodied.
These two clips are awesome examples of meta parody.
The first is a video I grabbed from cracked.com It's "A Trailer for Every Academy Award Winning Movie Ever."
A Trailer for Every Academy Award Winning Movie Ever -- powered by Cracked.com
This is the same concept but for the lyrics and music of a love song. I love Axis of Awesome. "How to Write a Love Song."
The end of the song where they talk about how this is a totally generic love song that could really be about anyone is all I can think of every time I hear a Melissa Ethridge or George Michael song. Stay away from those pronouns if you want to keep it mass marketable!