Not an official reply but if they don;t allow email lists to be bought or traded, I have a feeling that lead lists would also be banned. http://forums.digitalpoint.com/faq.php?faq=rules#faq_rules_topics
You'll have to tell us exactly what kinds of leads you intend to sell. If you're selling a list, not allowed (falls under the email list rules). If you're being paid for leads through something like surveys, also not allowed (falls under the affiliate link rules).