When choosing a domain name you should have a vision of your product or service, and it's market, and also with regards to Search Engine placement. The name Must Reflect the brand of product or service you are marketing, and encapsulate this in a short general term. But the single Most Important Factor is it must contain keyword(s) for the Search Engine Optimization. Also consider the domain name length, pronunciation, and how catchy and memorable it is. You will need to search different forms of the general phrase, to find if the name is taken in any other similar forms or extensions. Try to get a ".com" domain name if possible because most people, when trying a domain name in their web browser, will try it with ".com" at the end first, before ".net .org" etc.
If you find your choice has not got ".com" available but has any of the other extensions available do not choose one of these extensions for the reason previously stated. This would be very dangerous and might end up being confused for its ".com" counterpart, thus sending potential clients to your competitor. GoDaddy.com & InstantDomainSearch.com are excellent domain search sites.
With regard to Search Engine's the aim is to rank high in them, because the actual domain name contains the keyword(s) being searched for. It is most important that the domain name has a high probability of ranking at, or very near to, the top of the search engines rankings. A very popular tool used to find what is being searched for on the net is the Google Keyword Tool.
You must be very creative when constructing your domain name, most Domain Name sites have the function allowing you to try different variations of your name and to check availability.
Most Internet experts would agree that the shorter the domain, the better.
So in conclusion a domain name should be as short as possible, be catchy and memorable, preferably be a ".com" address, must reflect the brand of product or service you are marketing, and more importantly contain keyword(s) for the Search Engine Optimization.
"The first step to getting the things you want out of life is this: Decide what you want."
