Buying and selling affiliate sites is a professional trade.
The highest performing digital marketing experts for buying and selling digital assets understand many skills including:
Conversion Rate Optimisaion
Quality Content (using tools like marketmuse and surferseo to improve articles)
Technical SEO
Using high-quality link building agency
Silo Structure
Knowing how to package up a website that looks attractive to buyers
Mushfiq from The Website Flip is an expert at this so check out his interview here with Doug Cunnington: