title: Using Doctrine 2 and Repositories, what would be the purpose of a Service Layer?
body: <p>I'm designing my application, and I'm using Doctrine 2 and Zend Framework. </p>
  
  <p>Currently, I've wrote all my entities, I was going to start to write Repositories, and I though about Services, and I'm wondering if my Service layer wouldn't repeat the repositories.</p>
  
  <p>Is it worth to write a Service layer while I'm using Doctrine 2 repositories?</p>
  
  <p>However, I read here and there that a Service layer could be used to do caching for example.</p>
  
  <p>Have you any implementation example?</p>