There are exceptions though, like for GOG.com. Their downloader will allow for download resuming without having to get a new download authorization code, plus some other good features that's relevant to your account.
+1 and a big huzzah for the people running GoG.
How is it that those guys can "get it" so well - and almost everyone else misses it by a mile.
German ingenuity, one reason why I drive a German car.