Shares of Rite Aid (RAD -11.77%) were one of last week's biggest winners, soaring 30% after another blowout quarter. The once profitless drugstore operator has now surprised the market by rattling off four consecutive profitable quarters. Analysts were braced for deficits in three of those periods, including last week's report.

Sales inched marginally higher to $6.3 billion, fueled by a 1.7% increase in same-store pharmacy sales that was more than enough to offset a few store closures over the past year. Rite Aid now has 4,604 locations.

Investors trying to play the all-weather nature of drugstores have turned their attention to CVS (CVS -1.00%) and Walgreen (WBA -3.40%), and rightfully so. They are substantially larger, and they have been consistently profitable. The yields of 2.3% at Walgreen and 1.5% at CVS also help woo income investors. These aren't necessarily huge payouts, but they certainly beat Rite Aid, which hasn't paid out a dividend since 1999.

However, Rite Aid investors are the ones riding high these days. The stock has soared fivefold since falling below $1 this past December. 

That's a pretty spectacular return out of any retailer, but it doesn't mean Rite Aid is expensive. Rite Aid has been juicing up its guidance along the way, and analysts have no choice but to try to catch up by raising their own estimates. 

Wall Street's now eyeing a profit of $0.22 a share for this fiscal year that ends in February and $0.30 a share for the following year. The stock may have soared 243% so far this calendar year, but it's trading at a surprisingly reasonable 15.6 times next year's earnings. That's actually the same forward earnings multiple that Walgreen is fetching. CVS is cheaper.

Rite Aid isn't perfect. Debt is still clocking in at more than $6 billion. That's not as problematic as it was a year ago, given that the chain now expects to generate at least $1.24 billion in adjusted EBITDA this year. However, that's heavy leverage that needs to be noted.

We also can't ignore that non-pharmacy comps actually dipped 0.3% in its latest quarter. Rite Aid's turnaround has been largely the handiwork of cutting costs and improving margins. The real cheers will come when sales outpace inflation growth. After all, even looking out to next year, analysts are eyeing only 1% in top-line growth.

Rite Aid has still come a long way, and that's why a seemingly dead drugstore operator has been one of the biggest winners over the past year yet is still commanding a forward earnings multiple in the mid-teens. 

It can keep it up if it continues to deliver market-thumping results through improving margins, but sooner or later it's going to have to start becoming as popular with customers as it has been with investors over the past year.