1. People like numbers and really love lists, especially bulleted lists.
  2. Numbers promise bite-sized, easier-to-digest chunks of information.
  3. Lists are short and sweet, and cluster similar ideas for greater impact.
  4. Headlines that list a number make a concrete and credible promise.
  5. Lists are specific and quantifiable, which convey greater authority.
  6. Bullets are easier to scan but easier to grab the reader's attention.
  7. Lists are finite so they seem pithier and more efficient to read.
  8. People remember numbers more since they help to “hook” in the mind.
  9. Obscure numbers like 13 or 27 can catch readers' attention better.
  10. They often increase SEO because numbers come before the alphabet.

Photo: telegraph.co.uk