Facebook Home Invasion

Ribbon, an online payment startup, said on Wednesday that it had enabled Twitter users to conduct e-commerce transactions directly from links in Twitter posts. But less than two hours after the company launched its in-stream payments service, Twitter removed it.

Ribbon co-founder and CEO Hany Rashwan said in a blog post that the company's Twitter Cards integration was taken down without notification from Twitter. His post included a screenshot indicating that the company had validated its code using a test provided by Twitter to identify incorrect API usage.

"Before we released this, we made sure to validate our Twitter Card implementation, and all lights were green," said Rashwan. "We've had discussions with Twitter in the past, and are eager to find a way to work together. This is clearly something that's good for not only Twitter, but also for Twitter users all over the world."

[ Information is power. Read The Freedom From Information Act. ]

Twitter did not immediately respond to a request to explain the takedown. Like many platforms that support third-party development, Twitter has published API guidelines. It may be that Ribbon's payment system was deemed to be in violation of those terms.

Daniel Brusilovsky, head of business development at Ribbon, said in a phone interview that the service isn't entirely disabled. Ribbon previously presented links that, when clicked, led to a separate purchase page. That functionality remains. What's been disabled is the Twitter Cards integration that allowed purchases to be completed without leaving Twitter.

Brusilovsky declined to comment on whether Twitter had explained why it objected to Ribbon's use of its API, citing ongoing discussions with Twitter.

The knot in which Ribbon finds itself represents a possible entanglement for any company that hitches itself to another company's platform. As Twitter acknowledges in its API terms, its rules "will evolve along with [its] ecosystem." Absent irrevocable rights and service level commitments, companies have no guarantee that the platform functions they need will continue to be accessible or that the platform owner's interpretation of its rules and willingness to enforce them will remain consistent.

This is an ongoing issue. Last week, AppGratis, an app designed to help users find and download third-party apps from the iTunes App Store, was removed by Apple. Millions in venture capital and as many as 45 jobs at AppGratis are now at risk. And last year, a Twitter API rule change created a similar controversy among developers.

In addition to its short-lived Twitter Cards integration, Ribbon announced integration with YouTube. Using a YouTube feature called Merch Annotations, Ribbon users can now present links in YouTube videos that lead to Ribbon checkout pages. The payments company also revised its pricing, from 5% + 25 cents per transaction to 2.9% + 30 cents per transaction.