Optimize pdf file size using Ghostscript

We just got our conference booklet, and we need to publish it on the web. But, it has 152 Mb. This seemed excessive, so I googled a bit and found following: 

$ gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -dNOPAUSE -dQUIET -dBATCH -sOutputFile=output.pdf input.pdf

$ ls -al input.pdf output.pdf 
-r-xr-xr-x 1 dpavlin dpavlin 158511430 May 11 16:23 input.pdf
-rw-r--r-- 1 dpavlin dpavlin   1646309 May 11 16:24 output.pdf
That's reduction to 1% of original size.

-dPDFSETTINGS=configuration to presets the "distiller parameters" to one of four predefined settings:

  • /screen selects low-resolution output similar to the Acrobat Distiller "Screen Optimized" setting.
  • /ebook selects medium-resolution output similar to the Acrobat Distiller "eBook" setting.
  • /printer selects output similar to the Acrobat Distiller "Print Optimized" setting.
  • /prepress selects output similar to Acrobat Distiller "Prepress Optimized" setting.
  • /default selects output intended to be useful across a wide variety of uses, possibly at the expense of a larger output file.