Domain Names Can Be Categorized As Follows
1. Keyword Focused : Product and or Service in Name
Eg: TonneauCovers.com
2. Brand Name Focus: Both Existing and New Brands
Eg: Apple.com or Nxext.com
3. Location Focused : Search for area specific products and or services
Eg: TonneauCoversCanada.com
4.Product/Service Focus: Primarily Dictionary Words in Domain .
Usually 1 or 2 words..The Most Valuable Domains
Eg: Beer.com and Cars.com