Grannies wont get it
Back when they turned off the old 405 line analogue signal they claimed the switch over to 625 line was a sucess as only a couple of people complained. Well it wasn't quite the case.
When I was a toddler we used to go round to travel to granny's once or twice a year. We'd put the TV on but I could never watch kiddies TV (which I think just consisted of Playschool back then) in the morning, because it was on BBC2 and unknown to her at that time it was a 405 line set and BBC2 was only broadcast on 625 line.
The next year granny apologised that we couldn't watch TV as it had broken, and was just displaying static. What actually happened was they'd switched off 405 line signal, and the set was working, but now as much use as chocolate teapot. She didn't realise this, and didn't watch the TV that much anyway, so didn't want to complain.
The same thing will probably happen with my mother in 2 years time when analogue is switched off. She wouldn't have a clue that one of these boxes are needed, and wouldn't want to fiddle around with the aerial lead anyway. She wont have to as I bought her a digital ready LCD when the last set stopped working, but it needs an aerial upgrade as the existing loft one doesn't pick up any digital MUXs despite having a good analogue signal.
If its left to her she probably wont do it before the signal is switched off, and I will find her sitting there knitting in the dark, because she didn't want to complain.