tl:dr THEY SHIP PORN! schlick, schlick, schlick
Just look up an item you want to order. Then look for one of the following things highlighted in pink:
Add that item to your cart along with any other regular items you wish to purchase and checkout like normal.
So far I've gotten two smutty manga magazines and the Shoujo Sect Part 1 DVD Box I blogged about yesterday using this little loophole! The latter DVD costing me a mere $32.00 USD total including shipping which is about $25.00 less than the retail price on Amazon (minus any shipping charges)! :P That's a pretty sweet deal!
And, of course, if you’re looking for non-hentai stuff that is either out-of-print, cheap as hell or is an item that Amazon typically will not ship outside of Japan, you can use this little feature to add some more cool shit to your animanga collection without having to be a bitchslave to the proxy monsters!
abusing the system! Thanks pkChi for the tip!