I don't care about overall numbers which are inexorably declining. I understand folks no longer buy discs (nobody I know buys any and most have disposed of their collections). I no longer buy books (except for the odd coffee table movie book) and use my Kindle for it's convenience. All I care...
I am still buying discs, but not as many as before. It would be a lot less if it wasn't for KL in the US and some boutique European distributors. I am buying hardly any discs for contemporary films, so as long as deep catalogue discs are still being released, I'm still in.