I publish a 41mb InDesign newsletter monthly into interactive pdf. It always becomes a file size of 4mb, 10% of original, when I save to pdf. This month my newsletter is 41mb and it drops to 11mb, 25% of original. I have re-sized all pictures, deleted pages separately, have gotten the file size down to 16mb and it drops to 7mb, 45% of original.
I have gone back and saved Feb and March and it saves to 10% of original, as it did before, and I use the same mechanism to save now.
I have gone to Acrobat Pro and optimized down to 8.8mb, but the quality is not acceptable.
What other variable is there that I haven't discovered?