London is the world’s top Twitter city

London heads a list of the world’s major cities with the highest number of Twitter user accounts, followed by Los Angeles and Chicago, according to research by Hubspot.

Hubspot has also discovered that Twitter accounts that include a profile picture have ten times the number of followers than those without, based on an analysis of nine million accounts.

Using Hubspot’s Twitter grader tool, you can also score your own Twitter account for influence out of 100 points and see where it stands compared to more than 6 million accounts that have also been graded.

Top ranked Twitterers include Mashable, The New York Times & BBC News