Blue Nile (NASDAQ:NILE) recently reported better-than-expected quarterly earnings, thanks in part to growth in its high-end business. And Wall Street has taken a shine to the online jeweler lately -- shares are up around 60% over the last year. So should investors be making a lasting engagement with the engagement ring retailer? The Motley Fool's Mac Greer talks with Blue Nile President Diane Irvine.