For many years ever since we started manufacturing products for sale in the
offline physical world, we had been having sales agents representing
different manufacturers to help the latter to expand their markets. Their
main focus had been to make the sale by getting the orders from the
prospects and existing customers, which were then processed by the
manufacturers or merchants.
In the Internet online world today we have affiliates instead of agents. Affiliates are highly targeted pay-for-performance sales agents.
There are also some forms of Internet advertising that rewards the affiliates for driving traffic to the advertiser i.e. the manufacturers or the affiliate program owners. The advertiser pays the affiliates to place a link on their website, and the affiliate sends traffic to the advertiser in return. In other words, it's about the affiliates receiving commissions for helping in making the sales.
Affiliates are being considered as a complementary but very important sales channel although the merchants themselves continue to get their own direct traffic in making their own sales.