Commercials are always pretty short, 60 seconds or less. Audio books, or corporate narratives are many pages long. Even if you read a hundred page narrative or a book many times you still don't really know whats coming up next.
Practice having your eyes two to three words ahead of where you're speaking. You should not be saying the word you're reading with your eyes at the same time. Read ahead.
When you get to the end of a sentence and take your catch breath, make sure you always dart your eyes to the right to read ahead, this will reduce the number of flubs.
