There is no widely accepted definition as to how to perform a domain name appraisal. However the following factors are usually considered in order to get to a fair and reasonable figure.
1. Similar domain names that have previously been sold.
2. Similar domain names that are currently for sale.
3. Keywords and phrases in the name.
Generic keywords tend of have a higher value. Domains in specific niches, such as gambling, financial and adult entertainment, may may sell for more than other types of domain names.
If a domain name has one or two words, then they may be worth more than those with three or more words.
4. The length of the domain name.
Shorter domain names typically sell better than longer domain names.
5. The presence of numbers and hyphens.
Domain names with no hyphens or numbers will be worth more.
6. The industry the domain name will be used in.
7. How much marketing potential the domain may have.
8. If the domain could be valuable to the international market.
9. The entity that would most likely buy the domain name. For example if it is likely that a large company will want to buy the domain name, the value of the domain is based on that fact.
10. Future potential the domain name.
Overall, an appraisal must be honest. An appraisal that is done properly will assist sellers in determining a fair price for the domain name. Depending on the circumstances, the work conducted by an appraiser can also be used as evidence to justify the price to a potential buyer.