Blue Nile (NASDAQ:NILE) has an ambitious long-term goal: Persuade more customers to purchase expensive diamonds and fine jewelry online. It made steady progress toward that aim in the most recent quarter. The e-commerce retailer on Friday posted second-quarter earnings results that included accelerating sales growth.

Blue Nile also beat Wall Street's expectations on both sales and profits:

Revenue $111 million $114 million
Profit $0.19 per share $0.20 per share

*Expected is the average forecast of the six analysts who cover the stock. Source: Yahoo! Finance and Blue Nile's financial filing.

Quicker, more profitable growth 
The pace of revenue growth more than doubled to 7% from 3% in the first quarter of the year. Breaking that down a bit, Blue Nile sold 8% more engagement diamonds to customers in the United States and 4% more non-engagement jewelry. Meanwhile, international sales continued to climb at a quicker pace, logging 15% growth. "We made good progress on our key initiatives which delivered revenue growth and expanded profitability," said CEO Harvey Kanter.

Source: Blue Nile.

As it did last quarter, Blue Nile notched an earnings improvement even though its product mix tilted further toward relatively low-margin engagement sales in Q2. Gross profit margin rose to 19.4% of sales from 18.9% a year ago and 18.5% in the prior quarter. Net income inched higher to $2.3 million, or $0.20 per share, from $2.1 million, or $0.18 per share, in the prior-year period. 

Through initiatives like fewer promotions, more targeted marketing, and data analytics surrounding the online purchase process, the company hopes to raise its profitability over time while keeping sales marching higher. Blue Nile's 3% operating margin is far below the 18% that Tiffany enjoys. But, even without the same brand strength, Blue Nile believes it can slowly move toward that profit figure without endangering sales growth. "While this takes a bit of patience, we'll continue to move in a balanced direction," Kanter told investors in last quarter's conference call.

Outlook unchanged
Management kept their full-year sales and profit outlook unchanged, which suggests this  quarter's outperformance could have been driven by a handful of extra high-dollar sales -- rings over $50,000 a piece -- rather than a broad uptick in demand. After all, that unpredictable business segment was the reason behind last quarter's sales growth miss, according to the company. "This is a part of our business that is historically volatile and over time we expect growth in this area to return," executives explained in May. 

This year's revenue is still expected to be just below $500 million, or roughly 4% above 2014's results. Earnings should clock in at $0.85 per share. Both those updated top- and bottom-line figures are right in line with Wall Street's targets.