It's not really a loophole: you can't sell a digital copy because without a physical medium you can't sell _your_ copy. You could take money, and then transmit the bytes that make up the thing you bought to someone in exchange, but those bytes are copies of your version, they are not themselves the original.
Could you put your file on a harddisk and sell that? Again, no, because writing it to disk _creates a new copy_, so now you're violating copyright.
There's actually pretty solid legal argument for first doctrine not applying to digital media.
However, things get more interesting when you're selling your _license_ or your _access_ to some content. For example, can you sell your entire account to someone else, so that they now have access to what you no longer have access to? Depending on where you live: yes, you can.
> There's actually pretty solid legal argument for first doctrine not applying to digital media.
Of course there is. When someone uses a loophole, they’re doing something legal to get an unintended or nonobvious benefit— If an activity isn’t legal, it isn’t a using a loophole: it’s just fraudulent / criminal behavior.
The net effect of moving from producer-supplied media to consumer-supplied media has (among other things) resulted in a de facto curtailment of historical consumers’ rights, despite nobody doing anything illegal. The original drafters of copyright simply didn’t envision a world where products would be regularly delivered in a form that couldn’t be physically separated from the purchaser’s other posessions.
The original drafters of copyright have not been relevant to copyright law for an incredibly long time: we've revised it so many times that unless you want to invoke the most recent judges and lawyers involved, this argument has nothing to do with actual reality.
Could you put your file on a harddisk and sell that? Again, no, because writing it to disk _creates a new copy_, so now you're violating copyright.
There's actually pretty solid legal argument for first doctrine not applying to digital media.
However, things get more interesting when you're selling your _license_ or your _access_ to some content. For example, can you sell your entire account to someone else, so that they now have access to what you no longer have access to? Depending on where you live: yes, you can.