They do require payment though...

Summon Lesser Demon and Summon Greater Demon both require a vial of blood from a humanoid killed within the last 24 hours as a material component. So technically zero dollars, but not exactly free.

Never forget: If the service is free, you are the product

But the supplies required for the ritual often cost money. And Amazon drove the local ritual supply stores out of business.

So really, you have to pay with your soul twice, plus actual cash.

Do they take bitcoin? Asking for a friend.

Fact: nobody can prove that Satoshi Nakamoto isn't a demon.

I need to summon many demons. There are 1.1 million people as of the current count who I need to settle things with.

My summoned demon likes to join me in bed and then steal all of the blankets. I think that's why they were kicked out to Earth, their demon level is purely petty, like the straw falling into your paper cup.

It worked for Hermione Granger.

https://www.fanfiction.net/s/12614436

Mysterious Old Man: "Oh, there is a price. The important detail to iron out is who pays now, who pays later. Like when you all go out to eat and make plans for trying out that other place. Always a price."