Apologies if this has been posted elsewhere, had a look but couldn't see it anywhere obvious.
Noticed the fineprint on the TV ad for Lightbox that it's "now available on selected Samsung TVs" which appears to be pretty much any TV modern enough that it has access to the Smart Hub appstore, as my ~2 year old TV seems to work with it just fine. This has finally turned this into a potentially viable service rather than trying to watch it on a small screen or mucking about with trying to cast it to the TV.
Now to see how it competes with Netflix...