Twitter: On-Track for 200 Million Users by Year's End

"Twitter is on the cusp of becoming the next big, independent Internet company — or the next start-up to be swallowed whole by a giant like Google or, possibly, the next start-up to run out of steam."

That's straight out of a New York Times profile of Evan Williams this week, the departed CEO of the 140-characters-or-less messaging company. But that's not the news of the day—Williams might be out, but ongoing rumors of a slowdown in Twitter's user growth seem to be just that. According to the Times, the service is definitely more than just alive and kicking.

It's reported that Twitter's now up to 175 million users, which is itself 30 million users greater than the numbers that Williams was reporting in September—145 million. If you do the math, that's a growth rate of roughly 15 million users per month, or about half a million users per day. Back in April of this month, Twitter co-founder Biz Stone said that Twitter only had a 300,000-per-day user growth rate.

As well, Stone was reporting back then that Twitter had around 105 million users. We won't crunch the numbers again, but it's clear to see that Twitter's been undergoing some phenomenal growth rates lately. That's especially if you compare today's numbers to the kinds of figures that the company was touting last year—58 million users in 2009—or the meager 503,000 users that Twitter enjoyed three years ago.

So what does this mean, long-term? If its current growth rate continues, Twitter's sure to hit 200 million users before the year's end.

There's been no update as to how Twitter's users access the service or where they come from, however. In April, Stone was running with the figure that 75 percent of all Twitter's traffic comes from outside the site—external, third-party applications that tap into Twitter's service in various fashions. New updates like a redesign of Twitter.com and the addition of new interactive features alongside popular, real-world events likely account for a bit of Twitter's overall growth, but there's been no indication of just how much Twitter's lifeblood of third-party apps have contributed to the surge.