Detailed answer:
Modular Merchant allows you to turn your customers into a thriving, vibrant affiliate sales force with the click of a button. A customer can start earning commissions on the sales they bring in to your store simply be selecting the "Is Affiliate" option in the Customer Editor.

But, it's likely that anyone that's interested in marketing your website as an affiliate also knows a few others that would be interested too. In a multi-tiered marketing environment, your affiliates earn a commission not only on the sales that they generate, but also on the sales generated by anyone else that they get to sign up as an affiliate in your store.

Some shopping carts have a single-tier or two-tier marketing system. But Modular Merchant's affiliate marketing system is a multi-tiered system with no limit to the number of levels that can be instituted, allowing one affiliate's commission chain to continue from the affiliates that they sign up, through to that affiliate's sign ups, and on and on until their commission base covers all time and space.

The multi-tier affiliate module distributes commissions on a hierarchical basis up from the affiliate that generated the commission, up through each of their "parent affiliates" until reaching the end of the chain of affiliates.

For example, affiliate "A" joins the program and earns commissions for the sales they bring in to your store. If affiliates "B" and "C" to sign up after clicking on one of affiliate "A"'s affiliate links, all revenue generated by affiliates "B" and "C" will also result in additional commission (at a lower rate) for affiliate "A".

Let's look at a practical application of the system in another example: