The explanation is that the machine is only played when there are coin(s) already in the 1st three columns, so that they don't have to be spun from an empty state which requires more spins than it would if there are already coins in the column(s) when play is initiated.

I get it. You go around the casino vulturing this game just like you vulture multipliers on video poker games, and look for must hits within range.

So... approximately how many of these vulturable events do you find per hour (on average) and what is the average return per play? I ask this because I noticed WILD spins that returned very little.