Many web hosting companies, aka hosts, offer reseller plans. Why do they do that? why not just sell directly to the end customer and keep the profit? The reason is simple. The host expects you, the reseller, to help them advertise and expand their business. You are working as a salesperson for them, thinking up new and imaginative ways to bring in more customers. You can sell to people you know, people in your region or your professional niche; maybe you can run some sophisticated advertising campaign; or perhaps web hosting complements a service you are already offering, such as web design, hence giving you access to more clients.
Essentially, they want to increase the number of customers that they have. But there’s more, and this is something you should keep in mind. Hosting reselles pay for the hosting space upfront. Whether or not they actually manage to sell that space and make a profit isn’t the host’s business. Sure, they will do what they can to help you succeed, but the bottom line is you are buying hosting space from them, money in their pocket right away.