Unopened reddit stories are noticeably more interesting when viewed from a mobile device than from a system with a full display and adequate bandwidth. This is for the same reason that any movie in your DVD collection is less interesting than the same movie playing on TV.
With the mobile reading scenario I know the story might take a long time to load, or that my lame little mobile browser might balk at it — so there’s a decent chance I won’t be able to see it. With the movies, the one on TV is interesting because it’s going away soon.
It’s the same with relationships; your wife is Braveheart in your DVD collection, while the woman in line at the grocery store could very well be Battlefield Earth on cable (with commercials).
I think we are wired to be highly attracted to opportunities that are fleeting or difficult to attain, regardless of quality.