What happened

Shares of Petmed Express Inc. (NASDAQ:PETS), or 1-800-PetMeds as it's more commonly known, jumped as much as 18.8% in trading Monday after the company reported fiscal second-quarter results. The early pop subsided somewhat, and at 2:05 p.m. EDT shares were up 12.7% on the day.

So what

Revenue was up 7% in the quarter to $71.4 million and net income was up 23% to $10.8 million, or $0.52 per share. Analysts were expecting $72.2 million in revenue and earnings of $0.50 per share.

A small dog and a cat in the arms of a veterinarian

Image source: Getty Images.

One of the most positive signs for the company was that reorder sales, which measure customers who keep coming back to the company, were up 11% to $61 million.

Now what

Investors clearly aren't concerned about the slight revenue miss, and are focused today on the earnings-per-share beat by PetMeds. What's most impressive is the margin expansion from customers who keep coming back to the company for pet supplies. That's a sustainable long-term business, and that's why investors should be bullish on PetMeds' move today.

Travis Hoium has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.