The first autoresponders were created within mail transfer agents that found they could not deliver an e-mail to a given address. These create bounce messages such as "your e-mail could not be delivered because..." type responses. Today's autoresponders need to be careful to not generate e-mail backscatter, which can result in the autoresponses being considered E-mail spam.
Online surveys: Consumers are asked to complete a survey, including their demographic information and product and lifestyle interests. This information is used as a sales lead for advertisers, who purchase the consumer's information if provided. The consumer may 'opt-in' to receive correspondence from the advertiser and is therefore considered a qualified lead.