make them ALL available AFTER broadcast as well - FOREVER
they can make things so much more usable by catering for the exact opposite:
example: a 10 part series the wife and I watch broadcast in spring-summer 2016. it was on series record on our youview box. for various reasons didn't watch it until recently, at which point noticed 2 episodes missing (youview box was powered off due to being on holiday). went to iplayer to try to watch them - expired, no longer on iplayer. so now in order to watch those episodes I will have to go somewhere dubious to get access to them. why should I need to do that... ?
for in another example, there are numerous series that were on 10's of years ago before digital recorder boxes became commonplace (you name it, prize for the most amusing) that many of us might like to watch again. maybe we have them on VHS in the attic but the VCR long since died!
the disk and network space clearly must exists in the big bad-ass BBC datacentre to make them available to me. (if it doesn't, I'll build it for them).
this is the long tail of the distribution, watching the content months/years after original transmission that has very little impact on load but a massive impact on user experience / convenience factor.
Iplayer should simply make available everything the BBC has broadcast, ever, forever.