• by Wendy Davis , Staff Writer @wendyndavis, April 25, 2011

Argentinian ad network Smowtion, which earlier this month launched in the U.S., could be in for some pushback from privacy advocates.

Like many behavioral targeting companies, Smowtion allows users to opt out of ads targeted based on Web-surfing activity. Unlike many of its rivals, the company sets its opt-out to expire after only 30 days, Privacy Choice reported today.

Smowtion hasn't yet responded to MediaPost's requests for comment, so it's not yet clear whether the short duration of the opt-out is deliberate or a glitch. Either way, the company risks running afoul of deceptive practices laws in the U.S.

Earlier this year, ad network Chitika agreed to settle charges by the Federal Trade Commission stemming from opt-out cookies that expired after only 10 days. (Chitika said it intended for the cookie to last for 10 years.) Among other terms, Chitika said that in the future its opt-out cookies would last for at least 5 years.

Regardless of whether an opt-out cookie that vanishes after only 30 days is unlawful, it certainly doesn't seem fair to consumers to tell them they can opt out of online behavioral advertising only to quietly start deploying the technique again one month later.

Of course, consumers who eschew behavioral targeting by setting opt-out cookies have long faced the problem of disappearing opt-outs -- though that's often because users themselves, or their anti-spyware programs, delete the cookies. That's one reason why the FTC and privacy advocates are cheering the emergence of browser-based do-not-track headers.

Those headers, however, are only effective if ad networks agree to honor them. So far, few networks other than Chitika and BlueKai have made any move to do so.