I am old enough to remember Jessops in their heyday. I once visited their Leicester store in the early 80s and wandered around in awe. The staff knew their stuff and they seemed to have everything you could ever want.
I think their biggest mistake was to homogenise the look and feel of the stores when they expanded across the nation, and then dumbing down to compete with other high street chains. I can't help thinking that they would have performed better if they had built an affiliation of independent shops. That way they could have offered the personal touch that camera retail really needs, especially at the pro end, while gaining the benefit of group purchasing power. Euronics have managed this for white goods and it seems to work well.