At present, some companies call their project built on the principle of network marketing, multi-level affiliate programs. And there are no errors. If you open the site Wikipedia and type in the search 'affiliate program', we see that separately mentioned multi-level affiliate programs. But what definition of affiliate programs is given in Wikipedia: "Affiliate Program – Form business cooperation between the seller and partners in the sale of any goods or services. Allows the seller to reduce the cost of bringing the end customer. " Now let's look at one of definitions of the word 'marketing', this in Wikipedia: "Marketing – is the implementation of business processes in the direction of the flow of goods and services from producer to consumer." Based on this definition of the word 'marketing' can be conclude that a multilevel marketing – the promotion of goods or services from producers to consumers, realized at many levels. If we return to the definition of 'affiliate program', we see that it is one of the forms of business cooperation in the sphere of promoting goods or services. What this all can be concluded? Multi-level affiliate programs on the Internet are built on the principle of network, multi-level marketing, and difference between them and the classic affiliate programs only in how many levels. I would conventionally defined boundary in level 3. All that is within it – the classic affiliate, anything that has a large Number of levels – multi-level. We should also be said about affiliate programs pay per sale, with a very simple structure – single level.