Image Source: Stamps.com

What: Shares of online postage specialist Stamps.com (STMP) were up 19.1% at 12:58 p.m. EST on Friday after its quarterly results and outlook impressed Wall Street.

So what: Stamps.com shares have rallied in recent weeks on optimism heading into the quarter, and blowout Q4 results -- adjusted EPS of $1.57 trounced the consensus by $0.62 on whopping revenue growth of 67% -- coupled with upbeat guidance only reinforce that sentiment. In fact, adjusted EBITDA margin for the quarter increased to 43.2% from 30.5% in the year-ago period, giving analysts plenty of good vibes over the company's competitive position going forward.

Now what: Management now sees full-year adjusted EPS of $5-$5.50 on revenue of $290 million-$310 million versus the consensus of $4.33 and $290 million, respectively. "This was another exceptional year for Stamps.com with strong execution on our business goals, including the integration of our 2014 acquisitions of ShipStation and ShipWorks where we began to realize the synergies we expected from those deal," said Chairman and CEO Ken McBride. "This year we completed the Endicia acquisition, and we have begun working on the process of integrating their businesses into ours. Together, our three acquisitions have significantly strengthened our position in shipping, and we are excited about our opportunities in 2016 and beyond." Of course, with Stamps.com shares blasting to a new 52-week highs today, investors will have to consider whether those prospects are already baked into the valuation.