I try to purge ever six months or so. I go through Picasa and hide anything I haven't used it in a while. My hidden Folders is locked so they don't pop up. Then after six months, if I don't miss it, delete, delete, delete. My stash has basically come down to SSD stuff, stuff for the store I CT and my other CT, TLP, LDD, and SA. I have gotten really picky lately about what I buy.