Assalaamu alaykum. I want to ask you if the products that offer a money-back guarantee are permissible to promote and to get a commission from because I intend to start promoting products online and getting commissions (like putting images/banners of products on my website or blog and when the visitor will click on them and buy the product, I will get a commission). I mean, most of the time you can get a money-back guarantee when you are not satisfied with the product or when the product is not working or has some issues. The second question is: what about buying products or promoting products that have a warranty of one year or more; I mean, in case you break the product, they will fix it, or get you a new one, considering the fact that there are no additional fees imposed because of the warranty.

All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ʻalayhi wa sallam, is His slave and Messenger. 

The guarantee given on products is of two kinds:

First, the guarantee contracted independently from the sale contract for a fixed sum of money. According to this guarantee, the guarantor is committed to fix the product if it breaks down or to replace it within a specified interval of time. This kind of guarantee is prohibited because it involves gharar (risk and uncertainty) and gambling. The Prophet, sallallaahu ʻalayhi wa sallam, forbade the transactions that involve gharar. Abu Hurayrah said, “The Prophet, sallallaahu ʻalayhi wa sallam, forbade sales that involve gharar.” [Muslim]

This kind of guarantee is, in fact, a kind of prohibited commercial insurance.

Second, the guarantee to which you referred in your statement, “considering the fact that there are no additional fees imposed because of the warranty.”

This kind of guarantee is included in the sale contract according to which the manufacturer or seller guarantees that the product is free of technical and factory defects and that it is guaranteed to work properly within the validity period, if it is a device, for instance. According to this guarantee, the manufacturer or seller is committed to repair any factory or technical defect or replace it with another if needed. The preponderant scholarly view is that there is no harm in this kind of guarantee.

Hence, there is no harm that you market and promote goods or products with this kind of guarantee in return for a commission. Imaam Al-Bukhari entitled a chapter in his Saheeh: “Chapter regarding the commission of brokerage” in which he states, “Ibn Seereen, ʻAtaa', Ibraaheem and Al-Hasan did not see anything wrong in the broker's fee.” [Saheeh Al-Bukhari]

Allaah knows best.