Are you going to scan a single catalog and throw the rest away? That won't work because some have specific codes required, so you'll have to know which those are or perhaps scan every catalog cover. Some catalogs are going to be hell. Just to name a few: Sweetwater has a fairly long one; Blick's art supply catalog is bigger; Both are free and have wide distribution.
Where do you draw the line between package, parcel, and letter? What do you do when it is filled with confetti? What if it contains cash. Seriously.
Musical Hallmark cards anyone? Are you going to record them? No? Ok, then.
This is a neat idea and works for some things, but is also very seriously impractical and insecure for the customer, and a terrible mess on the business side.
Add to that that people (especially women I'm told, but I know of no studies to prove that) enjoy real magazines. I personally enjoy getting things in the mail. It is like a gift. I don't enjoy getting email.