When I open your e-mail in the morning and eagerly look for new golden nuggets of knowledge, I see a list under "Featured Articles". Then I click on one of those to get a snippet of the contents and a link to some (typically) great new material to read with my morning coffee.
But you're right. Off to the right, there is an icon that signifies when an article is really a commerical event. I'll learn to skip them in the future.