Like the author, I got into creating Runescape bots for a bit - but never works to sell them, just made my own for fun and (in-game) profit.
As I dove deeper into the world, I came across people who would purchase a monthly VPS and install botting software on it. There were plenty of guides on how to go through - but no easy solutions for those who weren't technical.
Realizing I had an opportunity to capitalize on this - I built up a hosting company dedicated to the Runescape botting niche. Each VPS would come pre-installed with all the required software and make it dead simple to begin botting within 5 minutes or so.
At my peak, I think I had over 100 dedicated servers each running anywhere from 4-16 VPS on them. Some of my customers were using it to level up their personal accounts, others were running gold-farming operations.
The business was fairly passive, and I learned a ton from the experience. Things eventually came crumbling down when the creators of Runescape broke the bots (This would happen on occasion, but things would be up and running within a day or two normally) for a long time. I had to shut down as all my customers left overnight.