Many clients insist on making sure that all the big points of a presentation are made by page 3. Why? Decades of boring PowerPoint has shown them that things past page 3 get lost in an endless stream of bullet points. Making sure your point gets made by page 3 means making sure that your point gets made in the first 20 minutes of a pitch.
The result: you are stuck in the middle. The story up to page 3 is too long to serve as a really crisp summary, and falls short on conveying the message with full impact (the real killer chart sits on page 37). A shame that people will switch off on page 4 and beyond.
Here is a better strategy: design a deck that takes 20 minutes to present with all the important points inside, telling your story once instead of saying what you will tell them (by page 3), saying it, saying what you just told them (slide 78).