Not sure if it possible, but the ideal leads would be email addresses of Betfair users!
Failing this, emails of sign ups for:
registered on horse racing forums
other gambling forums and sites, etc.
Emails need to be as fresh as possible and must be from of country where Betfair usage (UK, AUS, etc) is permitted.
I would need a sample of about 1000 emails, and a few days (max 5 days ) to test them.
All other details and offers can be submitted to PM box, but please only relevant to my terms described above.