This business name was inspired by the keywords "BEST" and "SITES". Catchy and easy to spell, and with excellent keywords to attract the search engines.
TheTenBestSites.com is a .com domain. Dot com domains are the most desirable top-level-domain in the world, famously used by websites like youtube.com. Once secured, a .com all but guarantees no-one else can outrank you for your own name in the long run.
Content or Membership website
App / service