title: HTTP requests optimization: What is the limit?
body: <p>It is common knowledge now to combine stylesheets and scripts in effort to reduce HTTP Requests. I have 2 questions:</p>
  
  <ol>
  <li>How expensive are they, really? </li>
  <li>When is a request too big it should be split?</li>
  </ol>
  
  <p>I cannot find the answers to these two questions in all online readings I did, such as <a href="http://developer.yahoo.com/performance/rules.html" rel="noreferrer">Yahoo! Best Practices</a> which states a number of times that HTTP requests are expensive, but never cite why or how.</p>
  
  <p>Thanks in advance.</p>