Twitter (TWTR) shares are getting crushed today after a disappointing earnings report

Twitter (TWTR) shares are getting crushed today after a disappointing earnings report. In a nutshell, investors were hoping for much quicker user growth than what occurred. In the fourth quarter, monthly active users reached 241 million. While that's up 30% from last year, it's slower growth than what the microblogging service achieved last quarter. Moreover, usage declined with 148 billion timeline views during the quarter, compared to 159 billion views in the prior period. That's definitely not good news for a company completely reliant on advertising clicks. Meanwhile, the company generated $243 million in revenues, with 75% coming from mobile ads. While revenues were higher than estimates, those aren't the numbers analysts are focusing on at this time. User engagement is a better measure of the company's future - and so far, Twitter still has some work to do in that area.