• by Wendy Davis  @wendyndavis, September 12, 2011

The microblogging service Twitter has suspended ad network Twittad and taken the company to court over the use of the word 'tweets' in its "Let your ad meet tweets" service.

Twittad was awarded a trademark on the name in 2008, but Twitter argues that the trademark should be invalidated because the word Tweet was already associated with Twitter by then.

"Immediately after Twitter's launch, the Tweet mark became widely adopted by consumers and media outlets to refer to Twitter," the company argues in a lawsuit filed late last week in U.S. District Court in the Northern District of California. "Prior to the public identifying Tweet with Twitter, the Tweet mark was not generally known to the consuming public beyond its dictionary meaning relating to birdsong."

Twitter, which launched in 2006, also says in its court papers that it was denied a trademark on the term Tweet by the U.S. Patent and Trademark Office late last year, partly because Twittad already used the word in the name of its ad service.

But Twittad founder and CEO James Eliason tells Online Media Daily that his company didn't face any opposition when its trademark application was pending. Eliason adds that Twittad had talks with Twitter co-founder Evan Williams as far back as 2008, and that Williams encouraged the ad network to "continue to experiment" to find an ad model for the service.

"From when Twitter launched through late 2010, there were no 'developer rules of the road' with regards to trademarking or using the word 'Tweet,'" Eliason says. "It is disappointing that Twitter suspended our Twitter account and that they have decided to file this suit against us, based on the multitude of facts in this case."

In the past, Twitter was not known for aggressively targeting other companies that used the word Tweet in their names. TweetDeck, which long co-existed with Twitter, was one well-known example. But Twitter purchased TweetDeck earlier this year and now says the acquisition proves Twitter is associated with the name Tweet.

"Twitter also owns a family of Tweet marks which are identified by the Tweet mark along with a short prefix or suffix -- such as CoTweet, ReTweet and TweetDeck," Twitter argues. "Accordingly, consumers would likely be confused by Defendant's trademark use of "Let your ad meet tweets."