salesforce.com (NYSE:CRM), erstwhile owner of the coveted quintuple-digit P/E prize, has always had its share of skeptics. (I should know. In years past, I was one of them.) But love it or hate it, you've got to admire the company's performance on Wednesday. Playing an away game on fiscal 2009 earnings, it shut down the crowd with authority.

I mean, just look at these numbers:

  • Q4 earnings came in at $0.11 per share using GAAP -- 83% better than last year.
  • Its ranks of paying subscribers rose 36%, helping sales grow 34%. CEO Marc Benioff boasted: "Salesforce.com is proud to be the first billion-dollar cloud computing company." (A claim that multibillion-dollar revenue shops like IBM (NYSE:IBM), EMC (NYSE:EMC), and Amazon.com (NASDAQ:AMZN) might take issue with.)
  • And the full year's numbers were even hotter: sales up 44%; profits more than doubling to $0.35 per share.

Management then proceeded to give higher guidance than the Street was expecting for both the first quarter of fiscal 2010 and the full year ($0.54 or $0.55 per share). And as for the skeptics who predicted that "customer churn" and "deferrals" of business would torpedo growth prospects ... they can react to salesforce.com's estimate that it will book more than $1.3 billion in sales this year. Nice.

And yet ...
Perpetual skeptics still have ample grounds to worry about salesforce.com. For one thing, the new guidance suggests that while sales will grow in 2009, the pace of that growth continues to slow. In fact, the midpoint of guidance (22%) suggests we could see last year's growth rate cut in half.

Maybe that wouldn't be so bad if profitability was keeping up. But here's the thing: Accounting profits may still be growing by leaps and bounds -- up more than 130% in 2008, and up 56% more next year, if all goes according to plan. But cash flows are another story entirely.

Despite the rapid ramp in revenue, salesforce.com grew free cash flow a bare 5% last year, to about $168.6 million. Granted, this makes for an enterprise value-to-FCF ratio of only 17, but we need to see something better than single-digit growth in cash flow to merit that multiple.

Foolish takeaway
Despite Benioff's boasting that "big-ticket software purchases just don't make sense" in a recession, Oracle (NASDAQ:ORCL) has proven it can continue growing cash flow at a double-digit clip over the past year, as has SAP (NYSE:SAP). Among the old-school software majors, only Microsoft (NASDAQ:MSFT) is coming up short in this regard. If salesforce.com wants to become the Microsoft of the software-as-a-service movement, slowing growth is the wrong way to imitate its idol.

For further Foolishness: