I'm not sure which store you are using, but any books bought through the Sony Reader Store are available for download/redownload at any time. If you want to sync you will have to use the Sony Reader Library app, which is sucky, but it gets the job done. (By sync I mean using the Sony Sync function--not merely adding books to your 950. You can sideload books via a direct copy from your PC, use a SD or MS card, use calibre, etc.) Any book downloaded via the Sony Reader Library app is stored on your PC.