Capturing Email and User Names


Hey guys,

If I had a website allowing users to log into our website with their Twitter account only, would I be able to retrieve their email account and username? And if so, where would this information live?

My team’s almost ready to launch our web app, and we would like to leverage our CRM to better understand our user base. We’re looking to understand the following things:

  1. Email: Match our Twitter follower and users who signed up for the app through their email accounts
  2. Email: When we have offline events that involve handing over email address’ to attend, match offline and online (twitter & users who signed up) participants
  3. Username: Identify offline participants that shared content around our offline events but have NOT signed up for the app

Your help would be highly appreciated.