Tickets. There is no known way to extract legitimate eShop tickets, and WUD tickets do not work with WUP install packages
"The Brazilians" (we really need a better name for this) have done 1 of 2 things: either 1) found way to extract legitimate tickets, or 2) found way to repackage WUD files as WUP install package and use WUD tickets
Since they're refusing to disclose the method, this thread is not interesting. I have no interest in their "warez" links other than reverse engineering what they did.