All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
There is no blame upon you as to the evaluation of a product as long as it is honestly and correctly described, taking into account that this evaluation is based upon your awareness of its quality and importance, and not relying on the opinions of others since they may incorrectly describe it for the sake of earning money.
The latter is totally forbidden since it includes cheating, misleading, and false testimony – all of which are matters declared prohibited by our purified religion that firmly warned us against them. Imam Muslim narrated that Abu Hurayrah reported that the Messenger of Allah said, “And he who treats us dishonestly does not belong to us.” In a narration recorded by Imam At-Tabaraani, He said, “He who treats us dishonestly does not belong to us and cunning and deceit are in the Fire.”
As such, honest evaluation of products is not blamable and there is no blame on the person on the reward he takes for it; however, dishonest evaluation and description are prohibited, and so is the money taken for them.
Allah knows best.