I read a big article about it, their "reasons for failure" perfectly describes how I felt about Sky Mall.
I myself haven't really read one in several years, though I fly a lot. I used to look at them after I got done reading a newspaper, back before wifi on planes. I do sometimes give them to my kids to thumb through, they love them (whale shaped boats and real Harry Potter wands and crap). I look at my phone, PC, tablet, etc now.
But, in my many years of flying, I have never once bought a thing from them.