You worked more hours but made the same amount of money. Therefore the amount you made per hour is lower than your usual amount.
But if you calculate hours worked and salaries. More often then not. There promotion for example made them earn less and less per hour.
But as someone wrote on hackernews: if your company is using the emotional path they don't have anything to offer on the rational level.
tl;DR: calculate your income per hour, not monthly salary!
Stealing this for my “don’t work for a startup” site!