Programs I use daily seem to create excessive temporary files or use up memory (Mail,Chrome, Word Excel, text editor) because I keep a several windows and a dozen tabs open plus edit numerous documents at a time. Several times a week, I find memory down to 2-3 GB, sometimes into mb territory. App takes 42 seconds to clean 1 TB drive with 24 GB memory, and I can work while its cleaning (does slow some programs down). While writing this review, my memory went from 12.29gb to 9.41gb with only Chrome open in the background. Not techie enough to understand why, but grateful that I can monitor this (icon in menu bar) so realize when to use it. Plus, in preferences I can set it to clean automatically from once it reaches a threshhold of 7,372mb or less (learned this today after writing that would be an extra I would like -- then checked preferences and found the option = I am no techie!)