Easy way to compress PDFs with Linux Terminal

gs -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/screen -sOutputFile=output.pdf Digitalbooklet-AG.pdf

/screen - is the low quality setting
/eboook - medium
/printer or /prepress - high