title: DAL and BLL in .NET
body: <p>There is this <a href="http://msdn.microsoft.com/en-us/library/bb288041.aspx" rel="noreferrer">DAL/BLL design suggestion</a> by Microsoft for ASP.NET (2.0) apps. I know some of the alternatives and I've read related questions here on SO. However I wonder if this proposed solution is worth implementing nowadays, is there a specific downside you know of?</p>
  
  <p>I want to develop DAL/BLL components for company-internal use, to access customer and employee data, etc from various applications and scripts. However before I start building that stuff, I want to be sure that this solution is 'good'. As example, the <a href="http://msdn.microsoft.com/en-us/library/aa581779.aspx" rel="noreferrer">BLL</a> passes datatables instead of encapsulating anything, you don't have isolated business objects that contain logic. It's basically only a dumb layer that eases the CRUD operations a bit and allows databinding for controls. </p>
  
  <p>Could someone, who has experience in this field, point me out the pro's and con's of this approach?</p>