Having a domain name that contains a keyword can be a good way to 'inform' your potential customers what kind of service or product that you are offering, search engines do pay some attention to this when it comes to categorising a website, but it is not a 'must' to have a domain with keyword. What I am saying is you should not over do it by picking a keyword stuffed domain name just to please the search engines, you should go back to the basic where a domain name is the image of your website and it should be short and catchy, easy to remember and brandable. Just remember, search engines may be putting in some weight on domains with keywords now, but this criteria can easily be taken away from their indexing algorithm without anyone knowing it until you found out your website has move down in search engine rankings, the bigger question here is are you able to follow the trend ? drop the keyword stuffed domain and change to another domain name again ? definitely not a good approach as this is the same as killing your website instantly.
It is not a good practice to change a domain name when so much effort has been put it to build up the publicity, have you ever heard of Yahoo/google changing their domain name ? You may have heard of the stories of the used to be PPC leader Goto.com changing to Overture.com in it's peak, where is the company now ? (it has been bought over by Yahoo and is now division in Yahoo marketing).
Therefore, do it right in the initial stage can save you from a lot of trouble in future.
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