What happened

Stamps.com (NASDAQ:STMP) has outgrown the market through the first six months of 2018 by rising 35% compared to a 2% uptick in the S&P 500, according to data provided by S&P Global Market Intelligence.

^SPX Chart

^SPX data by YCharts.

The rally put the shipping specialist at a new high, and the stock is up nearly 300% over the past three years.

So what

Stamps.com's postage and shipping business has been performing well, with sales up 27% in the most recent quarter and adjusted earnings rising 21%. Its base of mailing and shipping customers ticked up 3% to 740 million to start the year, while average monthly spending per user leapt 24% to $59. "We were very pleased with our first quarter performance," CEO Ken McBride told investors in early May. 

A customer receives a package.

Image source: Getty Images.

Now what

The rising demand for e-commerce deliveries promises to continue acting as a major tailwind to the company's operations. In fact, McBride and his team believe sales will rise to between $530 million and $560 million in 2018, compared to $469 million last year. Much of the windfall it's collecting from reduced tax rates, meanwhile, is being directed back at shareholders in the form of increased earnings and more aggressive stock repurchase spending.