Yes I skipped because it seems you asked the buyers. To answer the questions, I do not really ask buyers for reviews, even after they get their site. People giving reviews on their own and most of them posted their reviews after they got the website. I never contacted them again to see if they have earned anything. But I do checkups periodically. Most of the buyers did not do anything to their site after they got. But some of them did and I can see they are getting traffic (I checked using SEMRush & Ahrefs). Did not contact them either to know what amount they are asking. So unless someone actually wants to share by himself, I would not know. I am not like some dodgy sellers who give positive reviews to own threads.
Besides, the service is for the site development only. So buyers will review about how the site looks and their experience with the order process. We do not provide any SEO or content services further, nor do we provide any guarantee or earnings. So earning completely depends on the buyers. I hope I was able to answer your questions.