What works is exoclick, depends on your landing page and how you block all the bad converting sites the price to what you get from it great.
If you have more niched creators you have higher probability of success because of lower competition and lower costs.
You need to bare in mind that your return of investment might be 3-6 months really depends, as you might aquire customers that spends longterm. Not all the money in one month.
Another thing I would say is, that this traffic doesnt work with account with pay subscription