Even if the search engines consider them to be the same it still creates back links from within the site and this really doesn't hurt anything it could only help. When a blog gives the title and a breif description making you click over to another page is no different than on an ecommerce site where products are listed together in a catagory with just the title linking to the product page. It's more links within a site helping to make the customer stay on your site longer. External links are the traffic builders.