has made shipping packages easier for businesses. 

What: Shares of Internet postage company Inc. (NASDAQ:STMP) jumped 10.5% in the month of May, according to data provided by S&P Global Market Intelligence, after the company reported massive growth in the first quarter of 2016.

So what: Revenue jumped 86% in the quarter to $81.8 million and non-GAAP earnings per share were up 139% to $1.72. Some of the growth comes from the integration of the Endicia acquisition and resulting cost savings, but the large increase in earnings shows some solid operational momentum.

To put the market's surprise in perspective, analysts were expecting  revenue of $69.7 million and earnings of just $1.07 per share. On top of the earnings beat, management also said it expects full-year revenue of $310 million to $330 million and earnings of $6.00 to $6.50 per share.

Now what: is clearly gaining traction with customers large and small, surprising investors with how quickly it can turn that growth into profit. That's largely because mailing and shipping gross margin is a whopping 84.3%, giving incredible leverage to operational costs. If management can keep growing the top line and keep operating costs under control, there's tremendous upside for And with shares trading at only around 15 times earnings, I think the long-term future looks bright for the company.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.