Affiliate marketing isn’t a job. It’s a business opportunity.
That means that there is unlimited money-making potential. But it also means that how much you make is proportional to how much work you put into it.
That doesn’t mean that you have to make it a full-time effort, but it does mean that you have to keep working at it. It’s easy money, relatively speaking, but just signing up for a program and putting up a link or two doesn’t guarantee instant income.