There can be many ways to start a business through a website few of those are:
You can start a blog website and can earn through the website once it starts getting good traffic through google ad-sense, branding, advertising and affiliate too.
You can start a website in some niche and showcase the affiliate products with maximum details about it so that the visitor comes to your website for those details and once he/she is satisfied then can use the affiliate link which you have placed to buy the product.
Drop shipping website:
You can start drop-shipping whee you don’t have to keep any inventory and you have to promote some products and on receiving orders these are fulfilled by the vendor you are attached too and you get the difference of price just like you sell any product but the shipping, packaging all will be done by the vendor directly to the orders information shared by you.
although there are so many coupon websites still i think there is scope as most of these websites have expired coupons, if you keep track and make such provision that genuine coupons of various online offers are available on your website then you can get lot of traffic and here you can earn through the ads and affiliate links placed in between the offers. Also you can get brand promotion deals due to the traffic on your website.
You can create a review website for any product review it works best if you target a niche and not multiple categories, share proper reviews of the products and also keep provision where you get reviews from existing users which you can validate and allow to be published on your website. Here also you can earn through the traffic, ads, affiliate links and brand deals.
Product / Service Website:
If you have your product or service then you can promote it through website and from a single location you can do business in different regions, which without website is not possible till you don’t have a physical presence in the city or region. But website eliminates the need of physical presence and you can reach anywhere from single location to sale your product or service.
You can create a website for one or more fields of studies like for school students, or college students or professionals where test series and question bank can be made available for practice as these days most of the competitive exams are held online or in objective format.
If you have expertise of some course or you have someone known who has such expertise, then you can start an online course website as online courses and study is becoming more and more popular these days and if you have good content the you can earn a big deal through such websites selling courses.
Exclusive E-Commerce Website:
You can create an e commerce store where other people can keep their article and sell it and you can earn through the sales commission for providing a platform. In general, there are many such portals but you can choose some unique specific product like handicrafts which is not easily available online. You have to do good research for such product and manufacturers and if you find something unique then you can have a good market overseas of these products.
Online Listing Website:
You can create an online listing website for your city where only the businesses and services and other useful information is available only related to your city with updated contacts and complete location tracking , like the existing portals like just dial etc have incorrect information and if you target a specific area and create such listing website then you can earn from the traffic by getting ads, ad sense and even you can charge to the businesses listing once your portal gets good listing and traffic.
These are few ways to earn only through a website, there can be more such ways and you can also create an online store for FREE i have developed an app which is available on google play store named “Vanijya app” and also has a web panel where you can create your account for FREE and create an online store within minutes that too for FREE. All required for online selling is available for FREE and if you like you can subscribe its nominal subscription for additional features, else you can use it for free forever.