>>1509672Lesson two: Duping.
This is a huge problem(?) in the game at present because it's so easy to do. Basically when trading between accounts the server will happily give multiple copies of all the items traded if it receives multiple commands to do so.
Some dev has obviously noted this in the past and implemented a cludgy fix - the client throws you an error if you try to press "Recieve items" again up to two seconds after the previous tap.
However, whoever programmed their card database did an abysmal job of optimising it and the server often takes more then two seconds to process even a single-card trade, so tapping receive every 2.5 seconds will reliably multiply the items on both ends of a trade. The more cards there are in the bid (max 5) the longer that window is open, so tripling or quadrupling the bid is not uncommon. Other items can be duped, but only cards and kujatas will slow down the server to allow duping.
As you can imagine, with a multi account this lets you very quickly build up your deck and/or collection of ecchi girl cards by trading on the marketplace.
Elixers (equivalent to HP) have a lower rate of duping then cards and materials, and will usually double 50% of the time if you get a triple dupe; It's probably just a case of good timing on the second tap and enough server latancy. Because of this, it seems many dupers are unaware of this easy source of currency, so on any given day you can often spot them de-valuing rare cards on the marketplace.
The ones who do know are the hidden masses of cheaters who will quietly sit and wait for the cards they want. Recently a near-extinct card sold for 30,000 elixers.
Which is utterly rediculous.
It then got duped to infinity and spammed all over the market.