How is affiliate marketing considered an online business?

A website which have contents that makes money from ads and affiliate products how both of these consider as an “online business”?
share your point of view…

Because the marketing medium is almost all web based. Email, squeeze pages, online classifieds, etc.

Because Affiliate Marketing is a sales process. It is the process of selling other people’s products for commissions. It saves you from having to create, store and ship your own products.
And if you treat it seriously enough, yes, it can be a business, and a very lucrative one.

Affiliate marketing consider as online business because you cannot start well with affiliate marketing without your website because it help you get affiliate links which is needed to develop your affiliate marketing business.