A niche website can earn money by placing affiliate links from within the content and by placing Google Adsense banner ads as well.
Affiliate links or referrals work by rewarding you whenever one of your visitors clicks on an affiliate link and buys something. You would then be awarded a commission.
Popular affiliate programs include ShareASale, ClickBank and Amazon Associates.
With Google Adsense, relevant ads are displayed based on the content of your page. This is easier since you don’t have to find a product to sell yourself, it’s all done automatically. It’s also easier to make money, since you are paid per click – not per sale.