One of the greatest academic typos ever?
Knowledge Networks attempted to obtain mailing addresses for all sampled telephone numbers and succeeded in doing so for about 60 percent of them. These households were then sent advance letters stating that they had been selected to participate in a survey panel, that they would not pay any cost, that confidentiality was assured, and that a Knowledge Networks staff member would call them within a week. A $5 or $10 billion was included with the letter to encourage cooperation.
Yes. I would be encouraged to participate in that survey.
Source: Change, Linchiat and Jon A. Krosnick, National Surveys Via Rdd Telephone Interviewing Versus the Internet: Comparing Sample Representativeness and Response Quality, Public Opinion Quarterly, 73(4):641-678. URL: http://poq.oxfordjournals.org/content/73/4/641.short