Every time I go through movies I have bought and try to redeem the digital copy, I suspect the companies make the process so difficult that no one will actually do it. Companies like the gift card racket because they get the money and recipients hold on to them for far too long. Movie companies charge more for movies with the digital copy and make the process of redeeming them so difficult people will not do it.
Five were UltraViolet and one a Disney. All 6 required going to a different web page. Only one worked with the generic UV redemption page. Each other site had me sign in to UV from it. Two made me create accounts in other services in order to link them to UV. The Disney one was the oddest of all, it gave me a code that gave me Amazon promotional credit but was not clear about that so I had to risk buying the same movie at potentially paying more for the digital copy than I did the physical discs to redeem the code. (It did come across as free.)
I guess this is why I let them pile up for a few months before I go redeem them. An hour of work for six movies.