I've got a campaign running on that free voucher offer. I thought it would be a good opportunity to test how it works.
Very much B2B and I targeted my clicks so hard that I've received 60k impressions and 1 click in 3 weeks. Thinking of what sites i have live and going to target users in that vertical next to see how it goes.
Personally I think paying $50 a month for the premo membership and then searching for Business leads is much more effective then the PPC ads. But thats just me...maybe my ads are too targeted....
Let me know how you go