Even in a surging stock market, Activision Blizzard (NASDAQ:ATVI) stands out with its striking rally this year. Shares are up more than 75%, trouncing the broader market's 14% rise so far in 2017. Investors might be tempted to see that bounce as an opportunity to cash in quick profits. But this could be a case where the longer you play, the bigger your rewards.

Let's look at a few good reasons to stay greedy with this video game publisher's stock.

Two young men celebrate while playing a video game.

Image source: Getty Images.

Well-deserved gains

Activision's business is improving so dramatically that even its management team is having trouble keeping up. Executives beat their sales and profit forecasts for the seventh straight quarter in early November. They also raised their 2017 outlook for the third consecutive time this year.

The publisher is driving and taking full advantage of the industry shift toward digital content delivery. It logged a record $1 billion of in-game sales last quarter, for example, which generate a higher profit margin than sales through retailers.

Activision also notched a new franchise record for the Destiny brand, in part by making the latest chapter available for direct download from its PC-based sales platform. These digital initiatives have improved Activision's finances in a few key ways, including by raising profitability, smoothing out seasonal revenue spikes, and extending the useful life of its gaming titles.

More importantly, the developer is cranking out high-quality, engaging intellectual property, whether it's in established or brand-new franchises. Overwatch, Call of Duty, and World of Warcraft each played a key role in helping Activision set new audience records last quarter.

Options for more

That massive player base -- 384 million active users at last count -- is allowing Activision to expand into new areas and explore revenue streams that you might not associate with a video game company. The esports craze is helping produce a big market for spectator game viewing, for example, which opens the door for the type of licensing, consumer products, and advertising revenue that a company like Disney generates in huge quantities. Activision's new advertising platform is now rolling out on its casual gaming segment, which has seen its daily engagement level climb to a record 50 minutes per user -- on par with what Facebook enjoys.

Sure, Activision Blizzard isn't an entertainment giant or a social media company. But its deep content portfolio and massive digital platform provide plenty of avenues for the business to expand beyond its core video game sales.

The valuation isn't crazy

Activision's stock price surge looks more reasonable in context, especially given that bright operating outlook. Its 75% increase puts it right between two major rivals, with Electronic Arts (NASDAQ:EA) and Take-Two Interactive (NASDAQ:TTWO) having beaten the market and risen 138% and 38% in 2017, respectively.

EA Chart

EA data by YCharts.

All three publishers are valued at roughly the same price-to-sales ratio of 7. That's about double the valuation that Wall Street had assigned these companies in early 2015, but their businesses have become larger and more profitable since then.

Activision is the industry leader, and its Call of Duty titles have been the top sellers on gaming consoles in seven of the last eight years. It owns several of the market's biggest franchises, with Destiny, Candy Crush, and World of Warcraft covering three different but profitable monetization strategies. These are all good reasons that the stock could grow into a  premium over its peers in the years to come.