Once upon a time,
somebody saw a silver sports car. Although the black version was much cheaper, he was interested. The manufacturer promised that only 100 units would be sold of this special version, which also included silver wipers. So,
somebody happily agreed to the more pricey offer and even ordered two cars.
However, one year later, another 100 units of the silver sports car were sold. The car now only had black wipers but additionally featured a silver steering wheel.
Everything else was the same.
Somebody feeled deceived.
Arrrrrgggghhh, didn't they promise to sell only 100 silver units?
Somebody thought he should at least get two silver steering wheels for free. He did never believe in promises from this car manufacturer anymore.