Zippyshare is not a pay per download site, Zippyshare is a free upload website, like mediafire. You can upload passworded big files on sites such as zippyshare and mediafire and put a notice in the archive about the location of the archive's password. You can upload a txt file containing a password on any PPD site, promote your product for as long as you can and wait until download starts to flow. I don't think there are PPD/PTU websites that host files larger than 0.50 GB (well, excepting megaupload, and everybody know how that ended). And here's the moment where the passworded archives come in to play