https://marco.org/2007/07/15/i-used-to-work-for-a-major-consumer-products
I used to work for a major consumer products company and a simple way they increased usage of detergents and liquid fabric softener that wasn’t readily noticeable to the consumer was to increase the size of the cap on the top of the container. A ‘use’ was ‘one capful,’ so when the cap got just a bit bigger, consumers used just a bit more.