One of the things I sometimes think about as I squeeze a little dab of toothpaste on my toothbrush is all the commercials I saw over the years on TV where they showed the maximum amount of toothpaste possible to put on a brush. It took me year to figure out only a little dolip is more than enough.
Like this. Lots of unnecessary product used. Genius if you sell toothpaste.
One of the other great ones, the simple word "repeat" in the instructions for shampoo. Like a normal person needs to do two rounds of shampoo.
I saw an article that the average liquid laundry soap bottle has a cap way bigger than needed to measure out the proper amount for a load of laundry. Most people just use way more soap then is needed.
What marketing ideas can you remember that are just designed to get the customer to flat out waste the product faster than really needed.
Large portions at a restaurant don't count. You can always ask for a to-go box for the part you did not eat.