Robert Sapolski, professor at university of Stanford, on video below presents the study which was made in the beginning of this year. Actually, he found that the capacity of dopamine in the human brain is the biggest in the moment when people expect something to be given to them (bonus, additional payment, prize, etc). Dopamine is known also as hormone for happiness.
It is very interesting that humans are only mammals on this planet which could expect for whole life some prize which will be given in “another” world, after-life or something.
Please check this video, maybe you can find useful this method in your company to motivate your people.