The Twitter growth numbers tell us nothing

The March Twitter numbers are in: Traffic more than doubled. At least that's what's being reported. Unfortunately, the figure is almost meaningless.

Let's be very clear on the facts. A company called comScore reported today that the number of "unique US visitors" to Twitter.com grew 131 percent during the month of March.

This data excludes two groups of people: 1) the 95 percent of the world's population that doesn't live in the US; and 2) the people who use Twitter clients, rather than the Twitter.com site.

To the best of my knowledge, US users account for less than one-quarter of all Twitter users. Japan, the UK, Canada and Australia have much higher per-capita usage of Twitter (so the cultural impact is likely to be higher in these countries).

The comScore report ignores more than three-quarters of the Twitter user base. How did that change in March? We don't know.

Meanwhile, one of the most unusual things about Twitter is the explosion of third-party Twitter clients like Twitterfall, TwitZap or TweetDeck. Like Twitter growth itself, use of the different applications, Web sites and mobile clients people use grows at an increasing rate as well. I think. We just don't know. The comScore numbers completely ignore, well, me for example. I use third party clients, so I haven't been counted.

Did 1 percent of former Twitter.com users switch to third-party clients during March? Did 50 percent? We don't know. All we know is how many users were left behind.

Also: Third-party clients tend to change how people use Twitter. I mean, that's the point, right? In my case, I use third-party clients because they enable me to double or triple the number of tweets I can "consume." Is anybody counting that? Doesn't that matter more than "unique visitors"?

I'm not bashing comScore here. They were clear and presumably accurate in their reporting. But their results don't tell the whole story. In fact, they don't even come close to telling one-quarter of the story.

The bottom line here is that we need to take today's report with a grain of salt. It tells us only about the number of US visitors to the actual Twitter.com site. It tells us nothing about the overall Twitter population -- just one tiny minority of that population. 

In all likelyhood, Twitter "grew" by far, far more than 131 percent during the month of March. But like I said, we don't know and comScore hasn't told us.