Last month, Twitter added a setting to users’ accounts that let them enable anybody to send them direct messages, even if they didn’t follow the user. Apparently, that was just an experiment, and it has come to a close.

Traditionally, to send someone a direct message, they have had to follow you, meaning that for a private conversation to take place on Twitter, two users would have to actually follow one another. That changed with the experiment, when Twitter added this to the settings:

But that’s no longer an option.

Twitter never formally announced the feature, and it didn’t announce that it was taking it away.

Gigaom’s Matthew Ingram asked Twitter about it, and was linked to the company’s blog post about experiments.

“We are constantly evolving the product,” Twitter’s Alex Roetter said in the September post. “Some changes are visible –– they may help you protect your Twitter account or make it easier to share photos; others are under-the-hood changes that help us suggest relevant content in real time and make Twitter more engaging.”

In that, he noted that the experimentation has picked up in recent months at Twitter, so expect to see more features come and go as the company tries to get the formula right (which is all the more important now that it’s public).

[via TNW]

Image: Maryland GovPics, Flickr Creative Commons