Stricter rules on how developers can make use of its Twitter stream appear to be tied to the company's efforts to bring in more revenue from advertising and potentially other sources. To achieve that, Twitter believes it must provide a consistent experience for users who access its service, instead of the current hodgepodge of interfaces from third party clients.

That means tighter rules for developers, who are now being encouraged to develop within Twitter itself. But the way Twitter has communicated the changes, as well as the ambiguity of its guidelines - it hasn't said yet exactly what these "stricter rules" will entail - have stirred discontent among some developers.

The most recent scuffle began with a blog post two weeks ago, in which Twitter reminded developers it doesn't want them to build Twitter clients that mimic the "mainstream Twitter consumer client experience."

Instead, it wants them to focus on building "more interactive experiences within expanded tweets". It highlighted its recently introduced 'Twitter cards,' which are tweets that can be expanded with a click to display an image, video clip or the summary of a news story within the standard Twitter interface.

"The technology behind expanded Tweets... gives developers and publishers a way to tell richer stories on Twitter, directly within Tweets and drive traffic back to their sites," it said.

At the same time, Twitter began clamping down on third party applications that offer users alternative ways to view their stream. Most notably, LinkedIn said users would no longer be able to view their stream of tweets on its website, though they can still post tweets from LinkedIn.

Some developers balked, believing Twitter might soon shut them out, too.

"The mistake we all made with Twitter, me too, was to think a corporate API could act like an open protocol," software developer Dave Winer said in a tweet.

In 2010, Twitter hosted its first developer conference, dubbed Chirp. It appeared to be following the model of companies like Facebook and Google, except Twitter didn't repeat the event.

Jeremiah Owyang, an analyst at Altimeter Group, said it's not unusual for social networks that clamp down on their APIs' (application programming interfaces) use to see some backlash. "The initial approach is 'let a thousand flowers bloom,'" he said. "But then once they start blooming, the networks realize that they're missing out on monetisation opportunities."

Twitter declined to comment for this article, but it is reportedly eyeing other revenue opportunities as well, such as allowing users to make a restaurant reservation or even a purchase from within Twitter.

If expanded tweets are to take on more functionality, and become a greater source of revenue, it could explain why having a standard, dependable user interface is important for Twitter.

But the way Twitter has communicated its plans has likely made its problems worse than they had to be. Its move to tighten its API rules is "on one level fair, but on another level it drives developers nuts, because they were expecting one thing and now it's another," said Robert Scoble, an early Twitter advocate who does developer outreach for Rackspace.

Most companies that invite developers to build on their platforms warn them well in advance of upcoming changes, but Twitter doesn't, Scoble said. "Twitter just doesn't have that outreach to developers that makes you feel warm and fuzzy even when things are changing," he said.

IDC analyst Al Hilwa sees Twitter in somewhat of a Catch-22 situation: It needs a robust community of developers to continue its growth, but the steps it is taking to achieve that growth risk alienating its developers.

"Having a development ecosystem is one of those Holy Grails in tech. Not every company is able to do it, but it's a big plus if you can. It multiplies monetisation opportunities for you," Hilwa said.

IDG News Service