Do you think that whether you use powdered or liquid laundry soap is just a matter of personal preference? Have you ever wondered why if they both do the same thing why there's a difference? Well wonder know more, I've got the answer and explanation for you.
As far as I can tell people choose liquid or powder laundry soap based on 1 of 2 viewpoints. It was what their mother used and they have not problem with it or It was what their mother used and they have a problem so they use the other.
Basically, the major reason for choosing which kind of soap to use is humidity. Powdered laundry soap clumps together in areas where the humidity is high. Dry climates like the desert where I live, don't have this problem.
This I read said another reason to choose liquid over powder was due to hard water. They said that it wasn't dissolving well and not rinsing from the clothes or machine well. We've had hard water all my life and never had these problems. My best guess is that people assume that the scoop is the amount of soap they need when you really only need maybe the 1st line on the scoop for everyday laundry. Maybe more for dirty laundry.
So if you don't live in a humid area and are looking for a way to cut spending try powdered detergent or making your own. After all, why would you want to pay someone for something that's at least partly water when you have that at home. And if you really like liquid and would like to make your own, you can find lots of recipes out there or try this one.