I'm aware that a few have had Euro or Japanese releases, but they're pretty inaccessible for many fans - and Japanese releases do seem to be ridiculously expensive sometimes.
If they were to get UK releases via Shameless (or even Arrow) I think they would do well due to the inaccessibility of the other releases. But I do take your point, Paul, and I can often be found scouring the likes of eBay looking for hard-to-find titles. I just think it's about time the Giallo gained a wider audience and that fans new (and old) to the genre can readily get hold of titles.
For instance, when Shameless released The Designated Victim, it was a title I wasn't familiar with (hadn't even really heard of it, to be honest) and so I got a copy. I was knocked out by it, truly one of the greatest films I'd ever seen. I just couldn't understand why it was so little known. A real gem. Which leads me to wonder how many 'hidden gems' are waiting just to be (re-)discovered.