The problem with affiliate marketing is that it's thought to be an easy money making opportunity, nice mess and promote hundreds of products in a somewhat haphazard manner.
The advice we give is not to aim for profits by following the 'ndo cojo cojo' technique , but singapore phone number example rather to try the products you recommend first.
Are you a book blogger ? Recommend titles that you have personally read and appreciated. Are you a food blogger? Promote only the products that you have actually used for your recipes.
The web is unforgiving: one slip can be forgotten (maybe), the second certainly not.