Fitbit's gambit seems to have worked. After getting its stock battered during the past few months, the health-focused smartwatch maker gave investors a pleasant surprise on Thursday by announcing that it has shipped more than 1 million Fitbit Blaze devices in March, far surpassing expectations.

In fact, the $199.95 Fitbit Blaze is currently doing so well, it has managed to dethrone the $349.99 Apple Watch in Amazon's smartwatch category. Considering that the Apple Watch has been the leader in the e-commerce giant's smartwatch category for some time, the Blaze's performance is indeed quite exemplary.

Apart from the Blaze's impressive figures, the Fitbit Alta, a dedicated fitness tracker and an updated version of the company's popular Flex wristband has also managed to sell more than 1 million devices so far.

The company's announcement, together with the flagship smartwatch's performance in Amazon's online store and the Alta's figures, has encouraged investors. On Thursday morning, the smartwatch firm's stocks surged 6.8 percent to $14.31, a significant improvement over the firm's performance over the past few months.

Fitbit Chief Business Officer Woody Scal is optimistic about the company's sales figures.

"The positive response we've received to Blaze and Alta demonstrates our continued ability to innovate and drive strong demand for Fitbit products, which is what has made and kept us the leader in the global wearables category," he said.

Fitbit has largely been in trouble due to slowing growth and the relatively weak performance of the smartwatch market. Over the last three months alone, Fitbit's shares plunged 53 percent. In fact, when the Blaze was unveiled last January, investors were quite unimpressed, further pushing the company's stock downward.

As it turns out, investors were actually looking at a winning device then.

While the Fitbit Blaze does not have the full suite of smartwatch apps that popular wearables such as the Apple Watch have, it does have a number of novel tricks up its sleeve. Apart from being a dedicated health device, the Blaze is also able to interact with third-party mobile devices.

Plus, its battery life far exceeds its rivals, with the wearable lasting five full days before needing a recharge. In contrast, its rival, the Apple Watch, only lasts 18 hours on a single charge.

Though Fitbit still has a long way to go before it fully recovers, Joe Wittine of Longbow Research believes that the company is showing a number of encouraging signs. On Thursday, Wittine initiated the company's shares with a "Buy" rating and $20 price target, a full 40 percent above where the stock recently traded.