Twitter recently filed the appropriate paperwork for its IPO, which means that it may soon be a publicly traded company. That also means that investors are going to be going after its throat for increased revenues, profits and, along with those, growth. Internally, however, apparently the company is already missing its own growth goals.

AllThingsD said it learned that Twitter hopes to increase its user base to 400 million active users by the end of this year. That's a stretch, though, because the social network currently has a little over half of that at 240 million users. And it's not adding a boatload per month, either. AllThingsD said its sources reveal the social network is adding below 5 million users a month — right around 4.5 million. That's only 54 million a year. At that rate, Twitter would be lucky to hit its goal in a few years — and certainly not in 2013.

Maybe it set its targets too high this year and will need to adjust, but whatever it decides to promise its investors is going to be very important. Missed growth could end up in fear that the company has plateaued in some way — and that's not going to reflect well in future earnings, or its share price.