So promoting the affiliate product will be the best way for you to go. So what is the reason why promoting the affiliate product is the way to go?
If you have personally bought the product and you really know that it is a quality product, you will have no worry promoting it. Because when the people who buy the product from your affiliate link also knows that it is a good product, most of them will automatically sign up so that they will also be able to promote it.
If the affiliate program also have 2nd tier program, not only will you be earning the commissions that you earn from your sale, you will also be able to earn 2nd tier commissions. If you do it this way, you will be able to get better result as your 2nd tier affiliate may have already buy the product and they are more motivated to promote and sell the affiliate product too.
Even if the people do not buy your affiliate product, you will still at least try to get them to join the affiliate program. Unless you are really good in recruiting and motivating people so that they will sell more for you, I will not suggest to you to put in all your time and effort in promoting the affiliate programs.
So do keep in mind that you should promote more of the affiliate product and not the affiliate program. Promoting the product is the way where you will get all the incomes. But once you have more experience, your own product and affiliate program, you can then start to learn on promoting affiliate programs.