It seems 50 million is the magic number for popular mobile apps these days. Instagram reached the 50 million download mark just hours after Angry Birds Space surpassed the same milestone. Google Play has certainly helped Instagram soar in new sign-ups, hitting the 10 million mark over the weekend.

Mark Zuckerberg’s billion-dollar bet on Instagram just might pay off after all. The Facebook founder has uncovered another creative way to take over at least one aspect of the mobile landscape, as the social network’s IPO draws near and rumors of a Facebook-branded phone resurface.

Quantity over quality: Android taps more consumers

Mobile is certainly the key to consumers’ hearts, as Android-powered Samsung devices surpassed Apple iPhone shipments in the first quarter of 2012, according to a report out today from Juniper Research. That’s 46.9 million smartphones shipped by Samsung, compared to 35.1 million iPhone devices. Where Apple’s still winning, however, is in the revenue department. Apple’s mobile revenue, including the iPad, reached $29.3 billion, while Samsung’s entire lineup of mobile products were just over half that amount at $17 billion.

The margins for Android devices are typically lower than Apple’s, and it’s a compromise Android OEMs seem willing to take in order to appeal to the masses. As lines are drawn deeper in the sand, we see more distinction from each major OS including Android, iOS and Microsoft around price and accessibility. With the upcoming arrival of Windows 8, Microsoft’s revamping its mobile strategy for cross-device support. These plans were reiterated with their $300 million investment in Barnes & Noble’s digital division, and given their existing partnership and investment in Facebook, Microsoft is likely to be part of the social network’s mobile story as well.

Where does Android fit into battling ecosystems?

For Android, it’s Amazon’s power play with a retail outlet made accessible through the Kindle Fire that’s proven Apple’s most likely contender. Amazon’s ecosystem has become so influential that some wonder if a smartphone would play well in their future, expanding the Kindle’s success and extending access to its e-commerce offerings. This would be another low-profit margin tactic, according to analysts, and would fit nicely with Amazon’s integrated storefront features.

From Samsung to Apple, Facebook to Amazon, the smartphone market continues to present itself as an alluring opportunity to reach the consumer. As the largest open mobile platform in the market, Android is in a unique position to help or hinder its rivals and partners alike.