Forget the Fed, leading indicators, and a laundry list of economic gauges. If you ever want to take the pulse of Corporate America's heartbeat, Paychex (NASDAQ:PAYX) has typically been a good wrist to grab on to.

The economy rocked through most of the 1990s, and Paychex proved to be one of the best stocks over the course of that decade. As a provider of payroll services to companies, it's been the perfect proxy to measure the magnitude of paychecks being doled out.

Well, almost.

Last night, Paychex closed out its fiscal 2003 in healthy fashion. While fourth-quarter earnings rose by a mere penny for a $0.19-a-share showing, revenue soared by nearly 20%.

Before you begin assuming that the economy has fishtailed in the right direction and that Paychex customers are in a hiring frenzy, pause for the burp. That's Paychex excusing itself because it's been wolfing down plenty at the buyout buffet. With two significant acquisitions in recent months, let's temper that top-line buoyancy.

Its freshly acquired Advantage and InterPay subsidiaries contributed $26.5 million of the $289.8 million in May-quarter revenue. Neither company was part of the Paychex family a year ago. So back that out of the fiscal fourth-quarter revenue and its top-line growth is more than halved. Without Advantage and InterPay, Paychex would have grown revenue by just 7.8%.

Approaching the company that way is still impressive. Single-digit growth is better than going the other way and, while Paychex isn't cheap by any metric, it's a relative bargain to the ludicrous valuations of just two years ago when it peaked as it fetched 70 times trailing earnings.

Yet while acquiring companies is just part of doing business these days, don't ever lose sight of that slower organic growth figure. That's the platform-shoes-off, barefoot-height stick method to measure how well a company is really growing.

What did you think of Paychex and its fiscal 2003 earnings? Exactly what goes on in the payroll services industry and are the providers really making money off idle funds? All this and more -- in the Paychex discussion board. Only on Fool.com.