Reading through Walgreen's (NYSE:WAG) latest quarterly earnings report is a bit like stepping into the wayback machine -- or maybe the not-so-wayback machine. The third-quarter numbers look an awful lot like the digits from the second quarter, which is to say they're pretty good.

Sales growth? Check. Earnings growth? Check. Comps growth? Check. Well, check them again. The increases this quarter, while substantial, were a bit slimmer than the moves made in the second quarter. Still, there's little for shareholders to complain about.

Revenues grew 15% over the prior-year quarter to $9.6 billion, with prescriptions leading the way at a 17% clip. Comps were up a respectable 10%, with slight improvement in gross margins and administrative expenses; earnings came in 14% higher, at $0.33 per share. That was enough to beat analysts' expectations by a penny.

Investors are giving the results the financial equivalent of the golf clap, sending shares up around 2%, a couple of bucks off the 52-week high. The lukewarm response is likely owed to the present valuation of the firm: Shares currently trade at nearly 30 times trailing earnings. Earnings gains are estimated to be in the 15% range.

Walgreen is doing a solid job, but with competition from the likes of CVS (NYSE:CVS) and Rite Aid (NYSE:RAD), as well as discounters like Target (NYSE:TGT) and Wal-Mart (NYSE:WMT), it's tough to justify buying into a retailer with a P/E ratio that doubles its growth rate.

Interested in more Fool coverage of the drug biz?

Mathew Emmert's Motley Fool Income Investor serves up solid players like Walgreen that pay better dividends.

Fool contributor Seth Jayson likes to make bike trips to his neighborhood Walgreen, but he has no position in any company mentioned. View his Fool profile here.