I Have my own affiliate program targeted at bloggers and the goal was for my fellow bloggers to make money too. They could do one post about it , add a banner or text link and forget about it. From that point on, it’s passive income.
Now, I agree that a blogger should not rely on 1 income stream alone. If you have bigger ones, then do promote them but the higher the price, the more difficult to sell it. The smaller ones are easier and will add up at the end of the year.