I never bought anything in Jessops. I think there is a place for high street camera stores but they have to offer something that the Internet merchants don't, or offer something different from the pile them high and sell them cheap middle of the road SLRs, although they could offer these as well.
I don't know how Calumet are doing, but I tend to favour them. They have proper pro kit and people who really know their stuff to discuss it with. They offer a rental service for kit. They offer seminars and workshops to learn about your kit. And they run open days and other kinds of events in store. That makes you willing to pay slightly more than the box shifters on the Internet.
Having said that, Calumet didn't have something I wanted in stock, and I phoned Warehouse Express (Wex Photographic). The chap I talked to was very nice, knowledgeable, helpful and much better informed than I could ever remember a Jessops counter assistant to be. I got the impression he had actually used the camera I was referring to. So I bought it off them instead.
I think a high street store has to offer something different. Whether that is pro kit, secondhand kit, a film section, lighting, seminars or whatever. Otherwise the box shifting companies will win.