The most popular place by far is The main advantage of is that it aggregates data from a lot of different auctions and websites around the web. There are also paid services like DomCop. DomCom helps you identify worthy domains faster by displaying some additional data points that allow you to vet domains easily and in a unified interface. And finally, there are services that curate domains they believe are worthy such as’s newsletter.

What is a domain? Despite this word being mentioned so frequently, it’s often unclear what the functions and structures of domains are. Knowing the hierarchical structure of the Domain Name System (DNS) is fundamental for anyone working in IT or in any online industry. We explain the difference between top-level, second-level, and third-level domains, and how you can benefit from subdomains that...

It’s also not so easy to manually re-register. This is due to backorder providers which are paid to keep an eye on expiring domains over a certain period of time and then register them for the customer as soon as they become available. Promising expired domains are therefore usually sold before they have a chance to be put back on the registry menu for the public to look through.
You can’t tell us (with a straight face) that aged dictionary word .net and .org domains won’t sell easily. The .net extension is technically OLDER than .com, and holds an equally intrinsic value to that of its .com counterpart. These LLLL .com’s that are just letters slapped together may be cute to look at and easy to sell, but in the eyes of Google, ANY aged domain that makes sense (i.e. a dictionary word) is going to be much easier to rank for than some acronym or hodgepodge .com…and at the end of the day, that holds more value than whatever society sees in these nonsensical “” names.
So how do you develop that instinct? NameBio maintains a database of over 500,000 historical domain sales (as of writing this post). They have interesting filtering features by which you can narrow down domains by price range, date sold, keywords and more. Simply sifting through the listings on NameBio long enough will quickly develop your domain appraisal “instinct”.