My, how time flies. It seems like just last month that for-profit educator Corinthian Colleges (NASDAQ:COCO) was issuing its fiscal year-end earnings report. Wait. Yes, it was last month. Yet here we are a few weeks later, in October, and already the company is ready to return to Wall Street (Friday) and report its fiscal first-quarter 2006 numbers.

I fear Corinthian hasn't had a whole lot of time to get its act together in the eight weeks since the company reported its last batch of disappointing news. And from the looks of things, analysts agree. As of this writing, they're predicting that when Corinthian releases earnings Friday morning, it will announce that profits have declined by half since fiscal Q1 2005 -- that they collapsed from $0.16 one year ago to just $0.08 per diluted share in the quarter that ended in September.

Speaking of which, there's one bright spot to the proximity of Corinthian's two earnings releases: certainty. When Corinthian issued its guidance for fiscal Q1 2006, its quarter was already two-thirds done. As a result, the company was really peering just four weeks into the future when it advised that it expected to earn $0.08 to $0.10 per share.

As for why the company -- and the analysts -- seem so certain that earnings will decline in Q1, that belief likely stems from the very same problems we saw last month. Namely, while the company continues to grow its revenues nicely, the cost of that growth is soaring. We seem to have reached a point of diminishing returns at Corinthian. When a company has to increase its spending on salaries, marketing, and administrative costs by between 27% and 34%, just to rack up 21% more sales, you have to wonder whether those sales are really worth going after.

What I find most curious about the analysts' estimates, though, is not their prediction that Corinthian's earnings will decline. Repeating the obvious just doesn't impress me. Rather, it's the analysts' expectation that revenue growth is going to stagnate. They predict that the company will grow revenues by just 2% over last year's fiscal Q1 number -- and again in fiscal Q2, just a 2% year-over-year increase.

Now, an optimist might compare those minimal expectations to the company's 21% sales growth of yesteryear, and conclude that Corinthian can blow analyst estimates out of the water just by continuing to ramp revenues at its historical pace. After all, among Corinthian's peers -- Apollo (NASDAQ:APOL), Laureate (NASDAQ:LAUR), Strayer (NASDAQ:STRA), and Career Education (NASDAQ:CECO), for example -- no one else is predicted to grow more slowly than in the mid-teens.

And, yes, analysts could be wrong about Corinthian's revenue growth. But even if they are, in order for Corinthian to profit from growing revenues, it needs to get its expenses reined in. Only then can Corinthian resume not just growing, but growing profitably.

Ready for some happier news about Corinthian? Read it in:

Are you looking for an educational stock to add to your portfolio? Try the Motley Fool Hidden Gems newsletter, where Tom Gardner recommends an educational software provider that has yielded 41% returns since it was recommended in June. Start a free trial today to get access to every single recommendation in the portfolio.

The Motley Fool has kicked off its ninth annual Foolanthropy campaign! Nominate your favorite charities on our Foolanthropy discussion board through Nov. 6. For guidelines on what makes a charity Foolish, visit .

Fool contributor Rich Smith owns no shares in any company named above.