Non-exclusive "exclusive" toys at SDCC

As I search through the list of "exclusive" toys advertised to be at SDCC (e.g., from http://sdccblog.com/tag/exclusives/), I am amazed at how few of them are actually "exclusive" to SDCC 2017. It seems like most of them also have the option to be bought directly through the manufacturers website. "SDCC Exclusive" seems to actually mean "about a month before we sell them to the general public". I am fairly new to SDCC, but I have been lead to believe that a big part of going there is being able to purchase items that are truly exclusive to SDCC. Is this no longer the norm? Maybe it never was?