You can hire writers that’ll do it for you, they’ll charge $3 - $20 for a unique article.
The problem is that it’s extremely expensive but even if you make decent return on investment on it, or plan to, there is another problem.
Many so called professional unique content writers simply provide you with uber spinned, mega non unique content that can get you penalized.
This is the worst.
This is RISKY and expensive, therefore it is NOT a good solution for you.