| 摘要 |
Provided is a process for selecting candidates for participating in a market-research survey, or receiving other offers, based on location history while protecting privacy of the candidates. In some cases, the process includes: obtaining, at a survey-participant identification system, location histories from client devices, and the location histories indicating locations of the client device over time; associating each of the location histories with an anonymous pseudonym of the survey candidate; storing the location histories and the association with the anonymous pseudonyms in memory accessible to the server; obtaining, at the survey-participant identification system, criteria by which to select survey candidates, the criteria specifying locations relevant to a survey; selecting, with the survey-participant identification system, anonymous pseudonyms in memory that are associated with a location history that satisfies the criteria; and sending messages to the client devices inviting survey candidates corresponding to the selected anonymous pseudonyms to further identify themselves to participate in the survey. |
