It seemed odd that Coach's (NYSE: COH) stock took a tumble today, despite a seemingly decent quarterly profit. As it turns out, loose lips might sink ships, but clamming up can also sink a stock.

Coach's third-quarter net income increased 8.3% to $162.4 million, or $0.47 per share. Revenue increased 19% to $744.5 million. As in Coach's previous quarter, international strength helped bolster the company, despite the weak consumer environment here at home.

However, at my last check, Coach stock had fallen about 4% from yesterday. It seems that Coach's decision not to break out the difference in sales growth in its retail and factory outlet stores is bugging investors, along with the scant details it's released about its expectations for fiscal 2009.

Indeed, CEO Lew Frankfort's related blurb isn't comforting: "Beginning this quarter, we're only providing aggregated comparable-store sales for our North American retail and factory stores. While less detailed, this measure better aligns operational performance reporting with operational flexibility to respond to changes in market dynamics."

That doesn't exactly sound comforting. And while putting too much emphasis on short-term earnings guidance can impede long-term investors (as a policy, Google doesn't give guidance at all, for example), whenever a company decides to ratchet down the amount or granularity of information it discloses, investors have good reason to wonder exactly what it may be trying to hide.

Coach wouldn't be the first to make a move toward less disclosure; many retailers -- including names like Talbots (NYSE: TLB), Starbucks (Nasdaq: SBUX), and Bombay Co. (OTC: BBAO.PK) (the last of which is now literally a penny stock) -- decided to stop reporting monthly same-store sales figures over the last couple years, in what I consider a shareholder-unfriendly strategy. (And of course, Talbots and Bombay Co. had serious existing problems, and Starbucks was quite literally on the brink of a slowdown, when each stopped disclosing the monthly data. When companies reduce transparency, it's easy to fear the worst.)

Coach, which happens to be a Motley Fool Stock Advisor pick, is a company I like. It has done a great job of taking its luxury brand and spreading it to broader demographics, turning aspiration into an affordable luxury. However, I'm not thrilled that it's reducing the transparency of its sales data. Today's share price may be an opportunity, but I don't blame shareholders for wondering if there's something unpleasant hidden in Coach's bag of tricks.

Related Foolishness:

Coach and Starbucks are Motley Fool Stock Advisor recommendations. Starbucks is also an Inside Value selection. David and Tom Gardner have recommended a slew of stocks to subscribers since April 2002 -- to find out all about the service, take a 30-day free trial. The Fool owns shares of Starbucks.

Alyce Lomax owns shares of Starbucks. The Fool has a disclosure policy.