I could not find where the soul to be sold was defined. What is a soul?
Most here are taking the concept of soul from the movie idea. Which is likely what most Xian’s believe too since study is the furthest thing from a Xian’s daily routine.
But the Qabalistic idea is very clear and has everything to do with one’s blood, DNA, and evolution.
No way thats ridiculous.
Soul isn’t an object. It’s an emissive biproduct we create every second of every day. You can sell that or trade it. Soul is a residue. Nobody wants your residue. lol
In my experience of signing a literal contract to sell my soul to my uncle, I’ve discovered that we aren’t things. We are infinite, omniversal consciousness. To have soul is to be harmonious and ‘in the flow’. Many people are soulless zombies hypnotized by Beelzebubs psycho-social trance. I give a good bit of my soul to my uncle but I also give a lot to many other people, places, and things… You could see it as a river that eventually returns to the sea, or is distilled through rain, we all come from the same pool and we all meld and mix back into to it in the end. Everything that exists is eventually destroyed and distributed throughout the universe over time to contribute to many different new formations of things. No one can control that many variables to where your soul goes.
Nooooooo all my dreams are gone…!!! 
Hahaha what use would Satan have with our souls anyway?
Bumping for those who don’t know the resource stacked in this thread dealing with how to get practical results without any idea of selling your soul for someones lunch. 
If you are of the mindset that anything wants to snack on your soul i would suggest you dig into older mythologies. The emphasis on how much creation and the entites in it hold the soul in high regard are there for all to see.
But my soul is yummy 
We no want it. 
but you can get in line 8 for your brain chip.
But will I have success??
Ok ok I trolled enough 
With your brain chip and chakra implants yes. You will have all ze successesssssss 
I think my soul has gone sour…that’s why no one wants it
Sour soul? You need new implants.
Sad soul? Try focusing on some work with either the sun or a solar deity for a month.
Will the new implants give me a bigger dick too? 'cause if not, I don’t wanna bother.
Sad soul, sad panda…
They will but means new muladhara implants and those sting.
I might be interested…
Hahahaha.
^^
I wonder what is @anon47923162 's opinion on this as he is deeply into Franz Bardon’s work and Franz Bardon clearly states that selling one’s soul IS REAL.
Franz Bardon is probably the most important occultist in the last century in the west, so can’t take his opinion lightly.