Users can also opt out of Datalogix measurement studies at any time, Twitter said.
But in spite of the privacy considerations, the offline sales measurement will help to fill some informational holes for Twitter, said Brian Blau, an industry analyst with Gartner.
"Advertising platforms need to show how their services ultimately influence sales, and there haven't been many really effective services to do this type of offline tracking," he said.
"Having this data will certainly help advertisers better measure how effective their ad campaigns are on the sales of those products," he added.
Meanwhile, Twitter is continually trying to give marketers more effective ways to advertise on its site. In April the social network rolled out a feature to let advertisers place promoted tweets in users' timelines by targeting certain keywords or phrases.
The social network also has a television ad targeting program to let TV marketers push out branded content to people on Twitter if those users are tweeting about certain shows.
A recent Nielsen study suggests that Twitter's TV marketing program may indeed provide a revenue boost for the social network. The study's findings, announced Tuesday, showed that broadcast TV tune-in rates led to increased Twitter activity, and vice versa.
The television study may not be connected to Twitter's offline sales analysis program, "but I can say that Twitter is pushing the message that their service is a very effective platform for a diverse array of brands," said Gartner's Blau.
Twitter said it hopes to offer its offline sales measurement capability to more verticals and more geographies in the future.
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