title: Returning sum on value_counts
body: <p>Here is my DataFrame:</p>
  
  <pre><code>email            title       id
  ---------------------------------
  balh@blah.com    Title a    123
  blah@gmail.com   Title b    824
  new@blah.com     Title a    179
  </code></pre>
  
  <p>I'm calling;</p>
  
  <pre><code>counts = merged_df['title'].value_counts()
  </code></pre>
  
  <p>which returns:</p>
  
  <pre><code>Title a  2
  Title b  1
  </code></pre>
  
  <p>What I want to be able to do is return a sum of all the counts for all titles. So, in this case, I want to return the value 3. </p>