Sales Funnels Permissible?

Are Affiliate sales funnels permissible? Meaning if we sell a product (i.e a training programme) via an affiliate link, we continue to get comission for any future purchases from the customer (a premium membership etc.) JazakAllah Khair

Wa alaykum salaam,

This is questionable to me and seems to be against the Shariah principles.

For any gain and income, you must be doing a service, selling something or having an equity. To simply continuously gaining without any input in the future and have a stream of income with no further activity is at odds with Shariah principles.

Allah knows best