I just got the Feb issue of Kiplinger''s magazine (similar to Money mag)and they had a 3-4 page article about e-tailers of engagement rings and especially focused on Blue Nile and Whiteflash with a mention of James Allen. It was really interesting and said Whiteflash "is the lord of the online rings" interms of customzing and had good prices and Blue Nile was huge and had great prices. They also focused on cut as being the best way to judge a diamond and talked about GIA''s new reports that include cut info and of course AGS. One quote was very telling "For every dollar that Blue Nile pays suppliers for stones and settings, it sells finished baubles for $1.30. but for every dollar Zales hands suppliers, it sells items for $2." The article basically said e-tailers were the way to go!
