I do not know the exact method but I have encountered converted magazines which still retain the Zinio tags.
They appear to be produced by TeAM YYePG. email to:
yyepg@msn.com.
Zinio magazines are cumbersome, a little less so when you turn off the page turning animation. Having pdf files with thumbnails and bookmarks I think is more practical.
Reading lengthy text, even on a good quality screen like an iMac, is a chore, but these magazines can make excellent references when heavily illustrated with tutorials like some of the better British magazines such as Computer Arts and 3D World.