Summer is usually a pretty uneventful time for stocks of companies whose fiscal-year fortunes tend to be made or broken around Christmas.

But sleepy is not so bad if you're RedEnvelope (NASDAQ:REDE), a Motley Fool Hidden Gems pick that's whipped between $7 and $17 per share in the last 52 weeks alone. The company reported an expected loss of 20 cents per share and reaffirmed guidance for 20%-plus growth and positive net income for the year -- courtesy of reduced marketing, fulfillment, and general and administrative expenses going forward. Total revenues rose by 18.2% to $24,978, and share dilution was an acceptable 3%.

In addition, the company is investing in expanding its call center, preparing a number of new product offerings for the holiday season, (which, according to CEO Allison May, have been very well received in previews) and readying a loyalty program to debut later this year.

In my previous two articles on the company (here and here), I outlined three metrics specific to RedEnvelope that investors should keep track of.

First, revenues per order shipped jumped to $80, compared with $76 the year before. While this is a positive result of the company's expansion into jewelry, investors shouldn't rely too much on these boosts in price for continued growth. I think it's better to look at the number of orders shipped during the quarter, which rose by 12% from 278,000 in Q1 2005 to 312,000 in Q1 2006, lower than the 15% annual growth in previous two years.

Second, the customer file has grown to 2.5 million names and is keeping pace with a 500,000 annual increase of previous years. No problems here.

Third, my calculations show that the yield on this customer file fell slightly, as roughly 7.5% of existing customers returned to the website to place an order during Q1 2005. It will be interesting to see whether this number rebounds in the coming quarters as RedEnvelope rolls out some of its new products.

Last time I wrote about the company, I found the shares attractive at $8.75 and would still be a buyer at up to one times forward sales. But I encourage investors not to overpay -- while RedEnvelope may seem attractive on a price to sales-to-growth ratio compared with the likes of Motley Fool Stock Advisor selection Amazon.com (NASDAQ:AMZN), note that Amazon still has something RedEnvelope doesn't -- positive annual earnings per share. Instead, keep focus on the customer-file order yield and growth in total orders shipped -- these are likely to be the purest indicators of long-term growth.

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Fool contributor MarkoDjuranovic owns shares of RedEnvelope and no other company mentioned in this article.