title: What is the development effort for implementing "login with facebook" on large eCommerce site in JSP?
body: <p>I am trying to scope out the development effort associated with implementing the "login with Facebook" option on our website. 
  We operate a fairly large eCommerce travel website running on a JSP environment. We have already a user account feature, based on a MySQL database. The only requirement for a user to create an account currently is to provide an email address as their loginId and a password. </p>
  
  <p>In order to make it even easier for users to register and sign-in to our site, we would like to offer a "login with facebook" button (just like Kayak.com does), so that a user can register to our site based on their Facebook account. By authorizing our application, we would pull their email information and create an account on our website. </p>
  
  <p>My assumption is that this would be a relatively simple maintenance project, costing 10 Man Days of development &amp; QA max. I would like to get some feedback from other webmasters that have implemented a similar feature to see if my rough estimate is in line with reality. 
  Thanks in advance for the insights you can share with me. </p>
  
  <p>Lothaire </p>