Image source: Twitter.

Twitter (NYSE:TWTR) had a rough year in 2015. CEO Dick Costolo resigned, the company struggled with slowing user growth, and the stock plummeted 35%. Yet, as the following headlines show, there were some bright spots that point toward better times in the years ahead.

"Twitter rallies as Jack Dorsey returns in CEO role" 
-- Financial Times, Oct. 5

When Dick Costolo stepped down in June after a tumultuous five years as CEO, co-founder Jack Dorsey became interim CEO. The move became permanent in October, and Twitter's stock rallied 7% on the news.

Having Dorsey return to a more active leadership position within Twitter helped to restore investors' confidence in the struggling social media network's management team. More importantly, Dorsey's return has apparently reinvigorated morale among employees and has even helped to lure top talent back from rival tech leaders.

"CEO Jack Dorsey Gives a Third of His Twitter Stock Back to Employees" 
--, Oct. 22

Dorsey moved to further boost morale by contributing a third of his personal Twitter stock holdings to an employee equity pool. The shares amount to a 1% stake in Twitter and were valued at about $200 million at the time.

Actions like this make it easy to see why Dorsey is so loved by his coworkers. Giving away $200 million of his wealth in order to "reinvest directly in our people" is a remarkable gesture, and it shows that Dorsey understands and values employee engagement. It could also prove to be an excellent investment if it helps to energize Twitter's workforce and, in the process, put the company back on track for success.

"Twitter Unveils Curated News Feature Moments" 
-- The Wall Street Journal, Oct. 6

In addition to his employee-focused efforts, Dorsey has moved quickly to improve engagement among Twitter's users. New product rollouts such as Moments, which is designed to help users quickly find the biggest and best storylines currently on Twitter, are a step in the right direction.

"Twitter Dives Deeper Into Video With Periscope" 
--, March 12

Another Twitter product that continues to build momentum is Periscope. Twitter purchased the live-video streaming company in January and launched the app in March. Since that time, Periscope has seen rapid adoption, surpassing 10 million accounts by August, and was recently named Apple's "App of the Year" for 2015. 

Along with Vine -- the 6-second-video sharing app that has more than 200 million monthly viewers and delivers over 1.5 billion video views per day -- Periscope is helping Twitter become a force in video delivery. That should only grow in importance in the years ahead, with networking giant Cisco Systems saying that video will account for 80% of all consumer Internet traffic by 2019. 

"Twitter Aims Ads at 'Logged-Out' Audience" 
-- The Wall Street Journal, Dec. 10

Much of Twitter's promise lies beyond its core base of 320 million monthly active users. That's because Twitter has a massive opportunity to monetize the 500 million unique visitors that don't log in to its site. So it was big news when the company announced in December that it would start displaying ads to the millions of logged-out visitors who come to the site by clicking on Twitter links across the Web, in apps, or shared via email. 

Twitter executives believe this audience could ultimately represent a revenue opportunity of more than $1.2 billion. That would be a huge boost for the company, which generated just under $2 billion in sales over the past year. Still, it will take time for Twitter to ramp up these monetization efforts. So, as is typically the case with early-stage businesses, an investment in Twitter will likely require patience as the company moves to fulfill its potential.