We (Sort Of) Warned You: Twitter Boots Rival Ad Networks From Its Stream

Does your business plan involve running ads in Twitter’s stream? Think again: Twitter appears to have shut out all rival ad networks from its service.

The relevant quote from a Twitter blog post today: “We will not allow any third party to inject paid tweets into a timeline on any service that leverages the Twitter API.”

We sort of saw this coming. When Twitter launched its own ad system last month, COO Dick Costolo made it clear that Twitter would be restricting the way rival ad systems could use the service’s data feed.

But Costolo also seemed to leave room for ad networks like 140 Proof and Ad.ly. The supposed terms: If you use “real” tweets as your ads, you’ll be okay. Here’s an excerpt from an interview I conducted with him on this very topic:

Clients can use our system and other ad systems at the same time. The distinction I would make, or the caveat I would add to that, [is that] we are going to probably prohibit pieces, insertions into the timeline that cause user confusion.

So for example, if someone creates an ad that looks like a tweet in the timeline, but isn’t a tweet–such that if you click on the retweet button, you go to a landing page instead of retweeting the tweet–that’s something [that] causes user confusion; it harms the overall value of the platform, and we’re going to prohibit that.

What changed? I’ve asked Twitter for comment, but I doubt we’ll get more than what Costolo has already offered in his post. The short version: It’s our service, and we’re running it in a way that makes the most sense to us.

That’s fine, and that’s the company’s prerogative. But in addition to the third-party ad businesses Twitter just gut-punched, the move is going to have repercussions with Twitter’s third-party developers, who were already wary about the service’s intentions. It’s an open invitation to them to search for other partners. Like, um, Google (GOOG).

Meanwhile, TweetUp CEO Bill Gross, who is launching his Twitter ad product today, tells me his service won’t be affected by Twitter’s new policy because he’s not placing his ads in Twitter’s stream. Rather, he’s inserting them into Twitter search results his company generates. Seems to me that Twitter’s new policy is broad enough that it could be aimed at TweetUp too. But let’s see what happens…