Affiliate marketing is not my main business model, but I do make money doing it through my websites and through email marketing. You can run a legit business through just affiliate marketing but I don’t like to put all my eggs in one basket. It’s always good to diversify.
I only promote products that I actually use or have used. This is the best and most honest way to do it, because people will take your recommendations more seriously if you recommend a product that actually helps them.