Domainer is a term used to describe the person who buys and sells domain names, with the purpose of generating profit either by selling the domain names at a higher price later in time or from advertising activities. Domainers are sometimes referred to as publishers, domain name speculators, domain investors and commercial registrants. 
In order to earn income domainers generally register domain names based on seemingly generic phrases and hope for the increase in price, popularity and competitiveness for that specific domain name. Most domainers avoid registering domain names which contain trademarks as this is usually an issue of cybersquatting.
How To Become a Domainer
Nowdaways, it is not hard to become a domainer, but it is challenging to become a successful domainer. The domaining industry has been slowly reaching its peak and now more creativity and innovation are required. However, given the introdcution of new gTLDs via ICANN's New gTLD Program, the domain industry will undergo a drastic change and it remains to be seen how the domain name market will react. That is, hundreds to over a thousand new gTLDs will be introduced in the coming years, and consequently the amount of domain names, specifically premium domain names that may attract domain investors, will sky rocket. How this market will compare to the .com boom remains to be seen.
In general, a domain investor should be able to determine the most popular keywords that would be highly required in the near future and purchase domain names based on these keywords. In other words, the activity of domaining is mostly based on speculation. The domainer is able to sell the assets owned to any interested party, including premium or bulk domain name customers.
Domain Name Speculation Markets
As in the case of any other investment market, there are two types of domain name speculation markets:
- The primary market: where only new domain names are being registered and are being traded for the first time. These domain names have not been registered before and their registration is usually connected to new events. The launch of a TLD is a great opportunity for domain name speculators.
- The secondary market: this market involves previously registered domain names that are being traded for at least the second time. This is where domainers earn extra income by selling new, creative, popular and innovative domain names. Depending on the circumstances, a previously generic domain name may become a hotly contested and sought-after asset.