Affiliate marketing is a very good way to earn online. Affiliate marketing requires a source. That means you will need a platform to promote the affiliate product you are offered. Blogs are very popular as affiliate marketing websites. Affiliate platforms give blog websites more priority for product marketing. Moreover, if you have a lot of followers on twitter, facebook, youtube, instagram account then you can easily earn from here.
Even affiliate marketing requires a lot of experience including seo, website maintenance, marketing, economics, content writing, and more. I have tried to learn several times and failed but those who get success from here once will be able to earn a lot of money for long time.