Analysts should stay away from attempting to write articles about video games, this one is almost as bad as most of the ones saying that gaming on cell phones will kill the pc/console market.
"Despite major declines in total revenues between September 2012 and April 2013, the game has seen an increasing conversion rate for the its current, add-on, extra-game store, and its microtransaction revenues have held pat overall. What it tells us is that dedicated WoW players are interested in—and will spend money on—microtransactions. By bringing this system into the game, and allowing for powerups and performance-based microtransactions, WoW hopes to further entice players to spend."
It held pat because the same people who buy pets and mounts continue to buy pets and mounts as they are released. Gear would be an entirely new situation. If wow was to go pay to win they would probably lose about half of the paying subscriptions over night. If they dropped subscriptions completely and went microtransactions it would be such a giant upheaval that they would never catch up. There is no way to entice every player to spend more than what they were already paying, and there is no way to balance it enough that you don't anger people by forcing them to pay more in fees than they were paying for their sub.