Can you provide more information on this (what works, what doesn't)? I'm thinking of adding something like this to a nonprofit's website to help fund their mission.
In other words, genuinely helpful recommendations, not half-assed ads.
In general, services with recurring payments pay much higher commissions than single purchases.
Most affiliate deals are brokered through affiliate platforms. If you know your industry well enough and your own website is popular enough, you can broker your own deals with people that otherwise don't have a program.