He had been stuck at home for a few days. Not for any pressing reason, he'd spotted Astoria and her sister out shopping with Scorpius and the welcome sight of his son shook his belief that he had done the right thing in letting Astoria have full custody of the boy. So he went home so he wouldn't do something he'd regret, like going to Astoria and taking his son. He knew that wouldn't be a good thing.
Since he'd begun re-integrating himself into society again, Draco found the emptiness of the Manor suffocating. So, he did what Potion Masters do when they are bored. He went into his lab in the basement and began brewing all sorts of potions. Mostly, the more expensive ones, at least to those that didn't have family fortunes to fall back on.
In all honesty if he hadn't been dragged out of the lab at regular intervals by his slightly sadistic house-elf he probably wouldn't of even taken a break to eat.
After about a week of that, he had filled at least three shelves full of potions that he had no use for. Then an idea hit him. What if he used a place to sell them, not for his profit of course, towards something that he'd think of in the future.
Draco washed the last cauldron and his hands before putting it away properly (his lab was the only place in the Manor that Draco cleaned himself), he headed to his study and once at his desk, he began to draft a letter.
To the owner of the Yelling Compass,
I have a business proposition for you.
You have a shop, I make potions.
However, since few people trust my family name I would like to use your place to sell potions secretly. I don't want the payment for anything though. Keep it, donate it, throw it away for all I care. I just feel like doing something and this is the only thing I'm actually good at.
I am a tested and registered Potions Master, so nothing will be sold that is below exceptional quality. I can assure you of that.
Let me know what you think and get back to me as soon as you can.
Thank you,
Malfoy
After looking it over Draco nodded to himself, folded the parchment closed and placed it in an envelope. He sealed it with his Malfoy seal stamped into the dark green wax he kept on hand and stood to hand the letter to his owl Gerion. He knew his owl would get the letter there, so after watching him fly off, Draco went back to his lab just in case everything worked out.