Essentially every game which does microtransactions does it by implementing a dual currency system, with one free currency abundantly available if you have infinite time to play the game, and one currency which is only available through purchase (or very carefully monitored promotions). You sell the dear currency in odd-numbered lots (to exploit people's inability to do fourth grade math -- sad but broadly true of the industry), for example, 7 dragons eggs for $10, 15 dragons eggs (one free dragon egg!) for $20, etc. Even though this essentially enables you to price your Sword of Pwnage +1 at $1.42 (one dragon egg -- available ingame for one-click with no need to grab a credit card), you'll never actually send a $1.42 transaction to the processor.
> You sell the dear currency in odd-numbered lots (to exploit
> people's inability to do fourth grade math -- sad but broadly
> true of the industry), for example, 7 dragons eggs for $10, 15
> dragons eggs (one free dragon egg!) for $20, etc.
At the risk of embarassing myself through terrible fourth-grade math skills, can you explain how selling in odd-numbered lots is exploitive? Or do you just mean that at the $20 level it's not precisely one free?
I believe he's referring to their inability to divide 10/7 to calculate how much they're actually paying for each dragon egg, implying that he believes that if players knew each egg was almost a dollar and a half then they wouldn't purchase the eggs.
It is (explicitly, as a planned-and-tested-for-outcome) to cause players to not automatically attach "$3.50" to an in-game purchase which costs "3 dragon egs", thus not activating as much resistance to purchasing as it would if the prices were trivially calculable. (For instance, if you sold 10 dragon eggs for $10.)
You want to make it very obvious to people what they're paying for eggs, but very, very, very easy to spend eggs once they have them, both because a) it's in your best interest that they run out of eggs and re-buy them and b) because you will not be able to recognize revenues for eggs which are bought but not converted into in-game assets. (Revenue recognition for this is a deep and weird topic. Ask me some other time.)
There may also be a "hot dogs in packages of 8, buns in packages of 6" dimension to choosing the odd-sized in-game prices/currency-bundles. A user who has a little in-game change left may feel they have to add more, to get full value on their previous purchases.
I believe he's referring more to the fact that the real world price per unit of game currency is not a round number. If dragon eggs were worth exactly $1 each, people would be slightly more careful about the value/cost of in-game purchases.
