It is possible to make money via affiliate marketing links online, but it is not as simple as just posting links. Companies pay affiliates to post their links, but only if the affiliate generates leads and sales via the link.
Affiliate marketing is a way of making money by referring the products of companies or other people. Affiliates drive qualified leads to a company and are paid commissions. Successful affiliate marketing requires traffic and trust. An affiliate needs people clicking the links they post so that a portion of those people end up buying the product, filling out the form or taking the action that counts for the commission. Targeted traffic is necessary for affiliate marketing to work.
If viewers are not interested in what the affiliate is selling, they do not buy. A lack of trust results in the same lack of commissions. So affiliates need an audience that believes and trusts what they say and recommend, which is why good affiliates only promote services or products they personally use. Reputation is important for affiliate marketers, so they are careful in choosing products to endorse.