Well, a quick google search shows may reviews... Most common is a comment that it's not as cheap as you think, and Blue nile actually just acts as a middleman for diamond vendors. They don't inspect it themselves.
they are a well-known company in the US. Friend bought an engagement ring from them. Not the cheapest, but they have a wide-range/selection to choose from. Personally preferred to buy from brick and mortar shop so that i can see/choose the diamonds. Think that the article provided about blue nile does highlight the part about being able to see where exactly the inclusion is rather than just knowing how large the inclusion may be. hope that helps.