In term of payment or how commission are being derived, I think they are the same. Though they change the condition here and there, in short, the commission are derived from both your effort and your team effort.

However, I think there is a difference between MLM and Affiliate Programs.

In MLM, you treat it like your own business, you need to service your own customer, you need to coach and develop your own downlines, you must understand the product, the company and the compensation plan well such that you can teach or train others, network management is key for long term success of MLM business. Remember, it is your own business that you need to plan everything from scratch or follow the company system.

In affiliate programs, usually, you are just like a sale promoter, you refer new customers or new downlines to the company, or affiliate merchant, the company will do all the rest. They will train the downlines for you, they will service the customer for you. So, you are merely a bridge and you got paid when a customer sign up or you are paid whenever a sub-affiliate sign up.

That's my 2 cents thought on the difference between MLM and multi-tier affiliate programs.