Key Points to Keep in Mind before Buying a Domain Name
1) Avoid Exact Match Domains (EMD)Exact match domains are those domains which contain exact keyword phrase that you plan to focus on building your content on. For example lets assume that your intention is to provide people a platform where they can sell cars online, and you are focusing the keyword "sell cars online", and you manage to get a domain containing exact keyword phrase that is "www.sellcarsonline.com", you will not be granted with extra benefits by search engines.
Why You Should Avoid EMD?
You should avoid exact match keyword domains (EMD's) because google has altered it's algorithm and it no longer gives preference to the EMD's as it did before as mentioned by Matt Cutts, the head of Google Web spam team.