Twitter is still having a hard time attracting new users

Twitter reported earnings for its fourth quarter of 2014 on Thursday. The company reported revenue of $479 million, beating Wall Street's expectations of $453.6 million, which is up 100% annually and 33% in the quarter. It also crushed earnings estimates, posting $0.12 per share versus $0.06 expected. The stock went soaring after hours.

But Twitter's monthly active users (MAUs) were 288 million, versus Wall Street's expectations of 295 million.

Based on company data charted for us by BI Intelligence, Twitter's MAUs are up 20% from a year ago, but MAU growth continues to slow down. In the third quarter, year-over-year growth of Twitter MAUs was at 21%, and now it's at 20%. In the third quarter of 2013, growth was roughly 38%.

Twitter co-founder Ev Williams defended the slowing growth of monthly active users in a Medium post on Thursday, citing Apple as an example of a company that chooses to focus on "building the best product possible" and "selling as many [products] as possible to the same user," instead of "optimizing for number of people using their products." You can read his full post here.