Ha, well, there's a truth to that. I'd certainly agree that if I've seen a movie more than, say, two or three times and I still don't own it then I'm probably never going to, the occasional slipped-through-the-net exception notwithstanding. But I used to buy blind all the time , only to ditch most of them six months later, or a year later or whatever. I bought Withnail & I without having previously seen it, and I still hadn't got around to it when I upgraded it to blu-ray, and when I finally saw it I thought it was utter rubbish. Same with the Stieg Larsson "Millennium" films (not that I thought they were rubbish - they were good, just not for me - but that I bought them blind twice over before ditching them).
I still make blind purchases - I bought Savage Pampas a couple of weeks ago; I bought Massacre Gun nine or ten months ago, still haven't seen it - but I do it far less than I used to. I tend now to give things at least a look first, for the most part. A lot of it comes down to expense, too. I'll commit funds to my movie collection if I know the money's going to something I want but I couldn't afford to maintain a collection of films I may not watch again, or even like. Not to the degree I used to do it, certainly.
Plus, I've a nagging suspicion that storage space is going to become a serious concern within maybe another year, unless I cull a significant portion of my DVDS. So that's keeping me slightly more selective now, too. Still, if I like a movie I have to own it. Just knowing that I can probably stream it/download it - legally via Netflix, Amazon, Hulu etc. or otherwise - isn't enough. I need the officially licensed physical media. F*ck knows what I'll do once physical media is finally abandoned entirely in favour of streaming channels and digital downloads only. Give up collecting altogether, I suspect; wall myself, a blu-ray player and a monitor up into an igloo made out of my existing discs, maybe.