Okay, so who's been taken by a trade deal that was far from what it was cracked up to be? Examples of this are:
The pokemon you were expecting to receive was advertized as shiny or to have Pokerus but it turned out not to be;
The pokemon's IVs, EVS and nature were outlandishly different from what they were advertized to be;
Somebody took your valuable trade-to-evolve pokemon (shiny, flawless etc) promicing to send it back after evolution but neglected to do so;
You received an evolve by trade pokemon that was holding an everstone;
or anything else that makes it not such a deal.
I've noticed this to be extremely common in circles I've been involved with.
Got a story to share?