I only had some success with paid ads on reddit targeting r/aws, and it only lasted 3 months between March and June when competition was very low and I could get CPC rates around $0.10. From July onwards, I couldn't find availability for CPCs below $0.35 and that meant ads weren't profitable anymore. So I stopped. You can see more detail in the last graph over here: https://www.indiehackers.com/post/how-i-made-210-822-selling...

As for affiliates, they bring about 7.5% of the sales. Not the most important source, but it's nice to have. I onboarded almost all my affiliates from this one tweet: https://twitter.com/dvassallo/status/1273335185946238976 — I have about 100 affiliates, but 95% of the sales came from the top 10.

My own Twitter account is still the main source of sales: https://twitter.com/dvassallo/status/1333889974362488833