Microsoft (NASDAQ:MSFT) seems to be taking a page out of the Yahoo! playbook. In recent years, under Marissa Mayer, Yahoo! has been scooping up mobile app start-ups hand over fist as it acqui-hires developer talent. Microsoft is now starting a shopping streak of its own.

Reports first surfaced earlier this month that Microsoft had acquired Sunrise, the popular calendar app for iOS and Android, and Microsoft has now officially confirmed the acquisition. Could this be the beginning of an important strategic shift for Microsoft?

Source: Sunrise

That makes two
No financial terms were disclosed, but the prior reports suggested that Microsoft paid upwards of $100 million to acquire Sunrise. Sunrise had been gaining in popularity due to its smooth design and ease-of-use, combined with support for a wide range of devices and platforms. On top of that, it integrated with other popular third-party services.

The Sunrise acquisition comes shortly after Microsoft acquired Acompli for $200 million, an email app that was geared toward increasing enterprise productivity. After picking up Acompli in December, Microsoft rebranded the app as its new mobile Outlook offering for iOS and Android.

In doing so, Microsoft is now the proud owner of two mobile productivity apps that were beginning to take off in popularity. Of course, the teams of engineers and developers behind those apps now work for the Redmond giant, potentially paving the way for future mobile innovation.

A changing of the guard
If you look at Microsoft's purchase history, you can see that the software giant has started to pick up the pace of acquisitions. But there is also a notable shift in the characteristics of its targets.

Not long ago, Microsoft was making big, flashy acquisitions that could potentially catapult it into new areas. Sure, the September acquisition of Mojang for its Minecraft franchise made headlines at $2.5 billion, but it still pales in comparison to the massive acquisitions of Skype (May 2011 for $8.5 billion) or the Nokia handset business (September 2013 for $7.2 billion).

Source: Microsoft. Chart does not factor in acquisition prices.

Instead, what investors are seeing now are acquisitions that are more calculated, specialized, and importantly, cheaper. That includes Acompli and Sunrise but also purchases like HockeyApp (app crash analytics and distribution) or InMage (cloud-based business continuity), among others. Each of these acquisitions serves a specific purpose that fit within the broader goal of enhancing productivity.

It is possible that this strategic shift is attributable to Satya Nadella becoming CEO last year, particularly as he focuses intensely on the "mobile-first, cloud-first" era. It is worth noting that smaller acquisitions carry less risk as well. Microsoft took a massive $6.2 billion goodwill impairment charge back in 2012 and likely is not eager to do so again anytime soon.

Most of its peers, including Google and Apple, similarly pursue a targeted acquisition strategy, selectively scooping up small start-ups with talented engineers with relatively lower price tags. When it comes to acquisitions, "go big or go home" is not necessarily the best approach.