Every day thousands of domain names are expiring and some are not renewing by the domain owners. That’s good chance to make money.The list of every day expiring domain names with traffic details are available on tdnam and that’s good chance to own traffic domain names and good invest.

In the domain name market use letters to identify domain names
L - Letters
N - Numbers

Example :
www.earncow.com is LLLLLL domain name
www.7n7.com is LNL domain name
www.wow.com is LLL domain name

The domain names value depend on how many characters available on the name , Page rank , Alexa rank

And other important thing is try to register .com domain names because .net , .info , .org are not worthy than .com