At the time of the summer announcement, DoubleClick made it clear that its goal was to merge that information to create a comprehensive database.
"DoubleClick initially made a lot of statements about the positives of somehow tying online and offline data together," said Chris Hansen, a research analyst at Banc of America Securities covering online advertising services. DoubleClick was "very coy as to the specifics" of how that would be accomplished, he said.
USERS NEED TO VOLUNTEER INFO
But Jonathan Shapiro, senior VP-business development at DoubleClick, last week told Advertising Age that it is technically impossible to link a cookie, which is not personally identifiable, with a database of names and addresses. Rather, it would have to link names and addresses to browsers by having users volunteer that information, he said.
Analysts were hardly surprised.
"DoubleClick's intent was to be able to merge the two to match its online database with offline consumers and grow the database," said Jupiter Communications analyst Michele Slack. "But that is incredibly difficult to do [without] matching pieces of data."
Ms. Slack notes that privacy advocates are still concerned about DoubleClick's plans to create such a unified database, regardless of how it accomplishes the task.
"It definitely raises a red flag," she said.
Contributing: Ira Teinowitz.