Thanks to Mother's Day and the need to buy flowers for every woman in my life, I recently had the unusual experience of sitting on quite a bit more gold than I'm used to having. All I can say is that I never realized how easy it is to blow through it. Close fight in a street assault? Just keep clicking. Want to finish the boss event? How many refills could it take? And once you commit to using gold on something, you pretty much have to finish it due to sunk costs. You're not going to refill to finish bosses 136-141 and then give up.
I am used to hoarding my meager tapjoy stash like a miser, using it only in the most dire circumstances. Now that I've had the experience of being able to blow through a few hundred gold in minutes, I have a newfound appreciation for this game. I can extrapolate the psychological impulse to click "refill" repeatedly and imagine others who do the same thing with "Buy Vault." The same need to finish an event or battle that I've already sunk gold into is probably what drives people to keep spending to maintain their "lead" despite the fact that no one wins, there are no leaderboards, and it's obvious that the prizes we win can be taken away or rendered useless at any time.
It also sort of cheapened the feeling of finishing the event.
Not a good feeling.