• by Laurie Sullivan  @lauriesullivan, September 11, 2009

Twitter made changes to its Terms of Service (ToS) this week, adding a clause on advertising. Cofounder Biz Stone wrote in a blog post Thursday that Twitter plans to "leave the door open for advertising," but has no immediate plans to announce an ad model.

It's about time. Until now churning profits from Twitter has been the brainchild of third-party developers and companies tying advertising or marketing services to the site. And while the legalese makes it unclear as to what it all means, industry experts pick it apart in a way similar how they might scrutinize a long-tail keyword search engine optimization (SEO) or pay-per-click (PPC) marketing campaign.

Twitter's ToS doesn't spell out the type of advertising it plans to offer, but could include any type, even those as basic as a home page ad. It also could tie anyone's public status updates to a PPC ad.

Even Google could help bring in revenue, but when Online Media Daily tried to confirm that the Mountain View, Calif. company has either a financial or a friendly stake in Twitter, a Google spokesperson replied: "You know we don't comment on speculation or rumors."

Twitter terms state the company could tie advertisements to content or information on the services, in queries made through the services, or other information. Twitter will grant people access to the service, but using it means that Twitter or third-party providers and partners can target ads.

Some industry insiders believe that means Twitter could target people with ads related to keywords in tweets that either the person sends or receives.

Despite the fact that advertising on Twitter appeared inevitable, Connectual Managing Partner Aaron Goldman says it makes sense that Twitter would change the ToS now rather than wait until the ads go live. "That's a lesson learned from Facebook who changed their terms in tandem with implementing Beacon and we know the uproar that caused," he says.

David Berkowitz, senior director of emerging media and innovation at 360i, took the time to read Twitter's ToS, lightheartedly comparing it to a "good Grisham novel." Queries made through the services are subject to being targeted with an ad. "Updates from their terms of service in 2007 does not include advertising," he says. "It's an open question on whether they'll add advertising as a premium service. Or, do they want to cash out and let someone else figure it out? That doesn't seem as likely, now."

Some believe Twitter is blowing a lot of hot smoke and that the ToS doesn't mean anything new for advertisers, especially when drilling down to the fine print.

"Twitter is fond of saying they're about 'facilitating connections between businesses and individuals in meaningful and relevant ways,'" says Marty Weintraub, founder of aimClear, a search marketing company. "I'm sure that's true. For now they are leaving decorum to the wisdom of the mob. Administration and discipline therefore falls under Twitter's long-time ToS tenets: abuses in privacy, impersonation, trademark, violence, threats, copyright and other unlawful use. Past that it's still the Wild West, baby."

As Weintraub points out, the ToS also spells out guidelines for privacy, API, spam and copyrights. In fact, Twitter cofounder Stone puts content ownership in the spotlight by explaining that while Twitter can "use, copy, reproduce, process, adapt, modify, publish, transmit, display and distribute" tweets, the up-to-140-word-character blasts belong to Twitterers. Content ownership is something that Facebook has struggled with for some time.