BlackBerry Z30-Front-Logo

While BlackBerry still argues it has a positive future ahead, yet another major corporation is moving away from issuing BlackBerry smartphones in favor of competing operating systems. Pfizer recently sent a letter to employees alerting them to move from BlackBerry to Android or the iPhone after their regular contracts expire. The company currently has 92,000 employees, though it's unclear how many are currently using BlackBerry smartphones.

"In response to declining sales, the company is in a volatile state," Pfizer said in a letter to employees, according to Bloomberg. "We recommend that BlackBerry clients use their BlackBerry devices and plan to migrate to a new device at normal contract expiration." BlackBerry has promised to support its customers, even through worries of a potential sale that were eventually stifled when the company took itself off the market. Still, its BlackBerry 10 operating system wasn't accepted by consumers and the enterprise as warmly as expected, and it's unclear what the company's device plans are moving forward.

The company is currently in the process of rebuilding through a transition period and CEO Thorsten Heins recently relinquished his role. The firm most recently announced plans to layoff 40 percent of its workforce.