Market intelligencer Hitwise published new research yesterday about visits to the Twitter website, showing that such visits have been in decline since a peak in July.

The figures relate to visits by US users to the Twitter website, which follows a similar report from Hitwise in September. US users account for over 60 percent of all Twitter usage.

Yet such numbers don’t include the numbers of users who don’t visit the website but instead use Twitter to  interact with their communities via third-party applications.

Such figures could be significant and may skew interpretations of any metrics about how people user Twitter, including from what platform (desktop, mobile, etc), as I’ve wondered about before.

Hitwise says the decline in numbers is mostly due to Facebook’s dominance. That may well be so, but could it also be influenced by more people using third-party apps rather than going to the Twitter website? I think it’s a reasonable question but I can’t find anyone with an answer.

Then there’s mobile.

Mobile usage intrigues me most for four primary reasons:

1. Updating Twitter on the go is becoming easier literally by the day: it’s getting easier to access a network, cellular or wifi, almost anywhere you happen to be as those networks become more widespread, faster and more reliable.
2. The ways you can interact with Twitter from a mobile device are rapidly becoming more feature-rich – meaning, you can do far more valuable things to interact with your community than simply send and reply to tweets – as more Twitter apps become available especially on the iPhone, as some existing apps (with strong and loyal customer bases) evolve with additional features and functionality, and as more apps emerge that hook into Twitter (eg, mobile recording audio or doing online shopping and the app tweets your activity).
3. Ever more smarter handsets are coming from manufacturers ranging from Apple (iPhone), Nokia, Sony Ericsson, Blackberry, Palm (Pre), Android and others, all with a strong focus on the mobile web and apps rather than just making phone calls and sending text messages.
4. Especially in the US, there’s a clear trend in increasing overall usage of mobile devices to interact with content of all types on the web according to reports such as Pew Internet’s

Twitter and Status Updating, Fall 2009, which shows status updating and social networking “likely to grow as ever more internet users adopt mobile devices as a primary means of going online.” Pew’s view of the US is echoed elsewhere in the world in the latest monthly report from AdMob published yesterday showing strong growth in mobile usage in other major markets notably India, the UK and a number of countries in Southeast Asia.

So while metrics on Twitter usage such as those from Hitwise are useful pointers on what’s been happening, I don’t think they’re terribly valuable as predictors or even indicators without a more complete picture that includes mobile and third-party apps.

Related post:

• Is anyone measuring Twitter on mobile?