If I type this too fast, feel free to tell me to slow down.

You see, every time I write about this stock, The Motley Fool's disclosure policy requires that I then wait 10 days before trading in it. I feel duty-bound to tell you about the bargain I see in Blackboard's (Nasdaq: BBBB) shares after yesterday's post-earnings sell-off ... but pardon me if I'm impatient to get these 10 days over with as quickly as possible, so that I can buy myself some cheap shares.

Why the rush?
So here's the news that sparked yesterday's sell-off in shares of this educational software provider, Google (Nasdaq: GOOG) and Discovery (Nasdaq: DISCA) partner, and Motley Fool Hidden Gems recommendation. First off, the company beat revenue guidance, booking $63.2 million in Q4 sales, a 23% year-over-year increase. On earnings, Blackboard beat Wall Street's "pro forma" estimates by the proverbial penny, and earned $0.14 per diluted share worth of no-nonsense GAAP profits.

And what's better than GAAP profits? Cash profits. From my perspective here at the back of the class, Blackboard's news in that regard was even more impressive. The company generated a whopping $53.4 million in free cash flow over the course of fiscal 2007, more than four times its fiscal 2006 free cash flow, and also more than four times this year's GAAP net profit.

Valuation
So the way I look at things, we've now got a firm selling for 16 times its trailing cash profits. Analysts expect Blackboard to grow at about 25% per year over the next half decade, which makes for about a 0.6 price-to-free cash flow-to-growth ratio -- a "buy" in my book.

Guidance
Of course, the key caveat in the above is that analysts are looking at long-term growth potential. In the shorter term, investors may have been spooked by a slight decline in Blackboard's sales growth in Q4, relative to the rest of 2007. They were almost certainly spooked further by management's promise to grow revenue just 18% in the present quarter, and lose money in both Q1 and the year (under GAAP standards). Slowing growth and a return to losses? No one wants to hear that.

But here's what you need to hear: GAAP earnings often turn from black to red in the immediate wake of an acquisition. Off the top of my head, I can name a trio of cases where we've seen this happen in recent years -- at Symantec (Nasdaq: SYMC) when it bought Veritas, at Investools (Nasdaq: SWIM) when it bought thinkorswim, and at Natus Medical (Nasdaq: BABY) every other Tuesday.

Remember, Fools, that Blackboard continues to earn plenty of cash, and that it promises to earn more of that in the future -- making Blackboard a Grade-A student at a D-iscount price.

But does the Motley Fool Hidden Gems team agree? They're the ones who recommended the stock in the first place, after all. Find out whether they still consider Blackboard the teacher's pet when you take a 30-day free trial.

Fool contributor Rich Smith does not own shares of any company named above. Yet. Natus Medical is a Hidden Gems recommendation. The Motley Fool's disclosure policy has all the answers.