title: What is the best chart to visualize this data (number of users, number of users gained, number of users lost)
body: <p>I want to represent some data visually, using a visualization component.
  Now I want to represent this situation in a visual way: 
  Suppose I have an web application. I want to get an overview in a visual way about how users are reacting to it.</p>
  
  <p>Say: </p>
  
  <ul>
  <li>in Day1 I have 2 users: u1, u2</li>
  <li>in Day2 I have 2 users: u1, u2</li>
  <li>In Day3 I have 3 users: u3, u4</li>
  </ul>
  
  <p>It is useless to draw a line chart here. Because I'll be seeing a constant line. Although I have lost 2 users and gained 2 users in Day3.</p>
  
  <p>How to represent this data in a chart? The chart should give me an idea about: -</p>
  
  <ul>
  <li>total number of users</li>
  <li>number of users lost</li>
  <li>number of users gained.</li>
  </ul>